Code1racing

Has anyone on here had first hand experience using 305 heads on the 350 block. I've searched but all i see are theory based answers. I'd really like to know how it turned out for those who have, especially the success stories.

johnnyb1902

my buddy built a el-cheapo last year with parts he had laying around and put a set of 416s(had them cut for 1.94 intakes) on a 350 block it was 12 to 1 compression w/ a doug herbert 244,246-498,500 solid lift cam, out ran a buncha ls1 cars w/ it...never took to the track so cant tell ya any times. ahh not bad for a cheap motor.

92RS_Ttop

iTrader: (3)

I built my engine last winter using an early 70's 350 block and some 416 heads. Got them both for free from a friend who was cleaning out his storage to move and couldn't take them with him. It was just a basic rebuild, nothing real special. The block was in great shape, didn't need any machine work and hardly any cleaning. The heads I ported and cleaned myself and replaced the entire valvetrain but didn't have any machine work done on them. They still have the stock sized valves and press-in rocker studs with stock rocker arms. I did replace the cam and all the gaskets and bearings and had to have the crank cut .010" undersize. Reused the pistons and rods after a quick cleaning and topped it with a stock Q-jet intake manifold and a Holley 4-barrel VS carb. CR is calculated at 9.2:1. HP estimate is 301@4500, and torque estimate is 386@3000 using Desktop Dyno.

I've only run it one summer, and put about 3k on it so its not really even fully broken in. So far its running great, no complaints here and I've still got room for some upgrades if I want to down the road. I haven't had mine to the track since there aren't any near me so I don't have any actual numbers either. I never intended for the car to be a straight-line speed demon though. I'm happy with it so far, and there are so many other upgrades that it needs that by the time I get bored with its power level I'll be ready to build the 383 I really want to drop into it.

BASSETT IROC 85

iTrader: (2)

Seen it done several times. I would not waste my time. They build compression but run out of air about 4000 RPM. If I could not do better I would use them,but if you are building for power no way.

InfernalVortex

iTrader: (4)

It's kind of a moot question. SBC heads are sbc heads. 305 heads have smaller chambers, other than that it's about finding heads that flow the best, and some 305 heads flow better than 350 heads and vice versa. What really matters is airflow and compression ratio and if you find a 305 head that gets you in the right ballpark, go for it.

Only issue is 305 heads are going to have smaller valves which means more work to get the regular sized valves for a 4 inch bore in it.

Vader

Yes. This one has '416 heads:



It's still a dog, but with just a bit more bark. Even with an improved cam it didn't break very deep into 14s:



Bassett is correct. There are a lot better choices available.

8t2 z-chev

had 305 heads on a 350 in a '77 blazer-was ok but liked
to ping.

Jeffs82TA

iTrader: (1)

Just buy some L-98 "113" aluminum heads, they have 58cc chambers just like a 305. Lighter, less prone to detonation, flow better & relatively cheap these days.

Code1racing

Thanks Guys from what i see some have had success with it and some havent. I guess its the type of power and torque curve people are looking for. Also Like InfernalVortex said its all about airflow and compression. Ill give it a little more thought, and get back to everyone.

Damon

I've done it on an old low compression smogger 350, basically a stock engine otherwise. Did it purely to build some compression. Ended up making more power everywhere than the old -882 heads that used to be on it. A decent set of 305 heads, like the -416s flow about the same as the old smogger heads, so the bump in compression was about the only thing responsible for the extra power. Low end torque went up considerably- noticably stronger from the instant you step into the pedal. The improvement was less noticable as the RPMs climbed.

ls six

How about Vortec 305's? I'll be putting togrther a super cheap TPI 350 using LT1 style flat tops and some JY vortecs, I accept that the TPI will limit my peak productive RPM to proabably 5000 rpm with some creative porting and a mild cam.

So I'll be building for torque and going for CR and the 305 vortecs seem like a decent choice. The 305's also supposedly have smaller ports that may make port matching to the TPI base easier.

smithtc

iTrader: (5)

Don't recall cam specs off hand...mid .550 range, some overlap (I know thats not good details, will check later) Ported 416s on a 400ci with 350 trans and low gear, 4.xx, in a 70 Chevelle.

Low 8s in 8th mile spinning street tires. Lot of torque, lot of fun. Not good on highway and does run out of breath top end.

3rdgenmaro

iTrader: (9)

I have done it twice. Once for an older motor I had in my s10. Felt torquey down low, but like others have said it quit pulling above 4k rpms. couldnt pull enough air.

Other time was on a 90 RS camaro I had. Bought the car with the tbi 305. Guy didnt know what the oil dipstick was an ran it dry. I rebuilt a 350 bottom end with the 305 heads and tbi. I didnt drive it enough to really tell, but it was just a stock replacement that I done. I only built it to sell the car.

If I hadnt have already had the heads, I wouldnt have done it. If you have absolutely no money to spend and you already have the heads (and those heads dont need any work done to them) then go ahead. If not, just pick up a set of 350 heads. Most stock heads are very cheap and they will run better then the 305s.

Code1racing

Ok I actually have the heads laying around. My setup is actually a mid 70's 350 bored into a 355. I basicly have the factory crank and Rods with Flat Top pistons 4 valve reliefs. The Cam Im Running is a Lunati Flat Tappet .480 Lift with a duration @ .050 of 230 with a range of 2000-6000. an LSA of 109, and centerline of 107, and 1.6 ratio rocker arms. Of course the 58cc 305 cylinder heads, and A Weiland Air gap intake with a holley 750 double pumper. I have yet to do headers and Y pipe. I was Told this is a low 8 second setup in the 1/8th high 12 in the 1/4. But I took the car to the track for the first time on the build and Ran a 9.3 fastest in the 1/8. Im very unhappy with it. and yes my 700 Trans is built what am I doing wrong with this setup. Another thing I should mention is that it was my first time at the track, I dont remember breaking the tires Loose really bad either leaving the Line. Can someone help me out here, and tell me if it was most likely my driving or my setup.

F-BIRD'88

The 416 heads need a full porting to get the air flow up to make power.
In stock form they are modest at best. Takes air flow to make power.
Don;t expect much until you port them. 1.94x 1.60 valves best with full port effort. Needs more than a simple "pocket port". Don't be shy.
Do not do 2.02's on these heads.
The cam needs a recurved distributor curve. With much more initial timing at idle and a shorter advance curve. 24deg base at idle 12deg mech advance for 34-36deg total at max advance.
You must limit the advance travel. vac adv also needs to be limited to 10-12deg max.
Check your timing tab for true 0 TDC mark location Using a piston stop. I bet its out of wack. They always are.
That cam needs a 2800 stall converter minimum. A 3500 stall is best.
4.10's are what you need.
Stock exhaust manifolds are not going to work. Get long tube headers and dual 2.5" ex.
You can do a long tube header 2.5 into 3" or 3.5" single exhaust too.
The long tube headers make more power and torque than shorty headers.
Shortie type headers require a specific mergeing Y pipe setup and a different camshaft than the one you have. Advancing the camshaft in the motor more will help. If you have a stock converter you can advance it quit a bit to build launch torque. move it to a 102-103 intake C/L

Stock heat range spark plugs will be too hot. Run Champion RV8C or AC delco R42T gapped at .035" in the 416 heads. To maximize the compression ratio and net quench, if the pistons sit .025" or more below the deck at TDC install the 416 heads with a thin felpro 1094 gasket.
Minimum 92 octane gas.

Just slapping 305 heads on a 350 is just the start of the poor mans racing combo. This is how you finish it.
Easy 12's (low 8's in the 1/8th)

What was your MPH and 60FT in the 1/8th mile?

Code1racing

My MPH was 71.652 and my 60ft. was a 1.9 in the 1/8 mile. Thanks F-Bird'88. Looks Like I have some teardown and rebuild to do.

Damon

If you've already got flattop pistons you'll need a pretty thick head gasket just to get compression DOWN to 10:1. The chambers in those 305 heads are not very good at controlling detonation, so you may have detonation issues using them on that engine with that cam.

The only time I would recommend using them is if you've got an stock "smogger" 350 motor (dished pistons) and want to get the compression ratio up to make torque in a moderate RPM range, like I did, above.

Beyond that, you really might want to consider shelling out for some better heads with 64cc chambers (which you can get to a pump gas friendly compression ratio with much easier with flattop pistons). 350 Vortec heads, for instance, or something aftermarket if you've got the coin.

305sbc

iTrader: (3)

I didn't read it all, but for the most part I agree with Fbird88. He's usually right on.

I have a lot of experience with the 305 heads, 416's in particular.
I can tell you as 100% fact that the castings are identical to the stock 350 heads 083 castings besides the narrower chamber, and of course the 305 valves are smaller. The 416's take to modifications and air-flow improvement exactly the same way a 350 head does. The trouble is that too many people that go the route of 305 heads on a 350 do not make the effort to upgrade the head as this is considered a "budget" combination to build compression only. In doing this, many things such as valvespring upgrades or quality valvejobs are ignored.

This fact is not representative of the reality that 416's can be ported to the same point as a 083 casting, and have the valve sizes upgraded, along with deshrouding the chambers. When modified properly, which i have done, they are no more prone to detonation or running out of breath than a ported 083 head.

Most 416's will have considerable miles and will need the guides refreshed at the very least. This opens up the possibility to upgrade to LSX valves with larger heads and thinner stems. With proper porting and this valve upgrade, the 416's can come very close to equaling several aftermarket aluminum 350 heads in terms of air-flow.

The 305 head swap used to be very common with some dirt racers before the norm became 400+ cubes. They could get the heads dirt cheap or free, build high compression, and easily modify them for good flow. DIY porting is the cheapest route of course.

There are a couple of links in my signature to information about the LSX valve conversion. There are many advantages to this upgrade that I won't go into here, but you can read about most of them at those links.

I have a few pictures of a ported 416 head here:
http://s702.photobucket.com/albums/w...3/305%20heads/
And here's one with the LS1 valves in the chamber. The valves start out as 2.00/1.55" but become slightly smaller after being radiused. The valve seats in this picture have been opened up to around 91% of the valve diameter. These seats have the normal 45* seat on the valve and 46* seat in heads.

SSC

Yes alot of them! This is the engine that came out of my truck to replace the 250 inline 6 in the wife's Apollo. Yeah a BBC looks too good under the hood of my truck! 383 with 416's it has 1.94 vales with some mild porting done. Has no issues running pulls very well to 6800 the few dozen time I spun it that high. That said I did have some issue with spark curve in the truck and pinging with crap gas. Seems that all went away in the Buick less weight.

F-BIRD'88

You are more likely to come up short on actual measured cr than too high.

1. the piston is most likely well below the deck @TDC. (measure it)

2. When you sweep the chamber wall around the valves on your 416 heads the chamber will be
larger than stock 62ish cc is typical.

3. The cam you have needs compression to work. It also stinks unless the exhaust system is right. needs gear and converter stall too.

Don't be spooked, leave the gasket thickness decision until you have measured the piston deck clearance and CC'd the finished heads.
When the engine is set up properly with the right plugs,timing curve and carb jetting it will handle all kinds of compression ratio. You will need to put decent premium hi test pump gas in the tank.
A high performance engine needs a high performance fuel.

measured 11:1 is too much. 10.5:1 +/- is where I'd work to get with this one.

The success of this head swap is highly dependant on the details.

At 71MPH in the eighth mile this car was way off the power mark.
You need to take the cork out of the bottle. (fuel volume delivery , exhaust system) The engine has to breath from air filter to tail pipe to make power. Start with a simple engine compression test to see how healthy the engine is.
A sick motor as not going to make power reguardless of what you do. If its sick now is the time to deal with that.

It all has to work together.

kd5icr

iTrader: (2)

If you are going to run a carb on that setup and you have a dizzy that has vucumn and mechanical advane you can play around with both and take care of any "ping" and still run pump gas. It's all about the basics. With a good intake and exhaust you can run 305 heads and still get good numbers at the track and have a DD that can put up a fight.

edwinlc

Im running a 1973 010 350 4bolt main in my 85 iroc. This motor has 305 heads 601 castings, unshrouded the valves and did a little mild port and polish job on them. Also have comps cam screw in studs and guide plates for strength. Also stuck a comps cam xe 262 in it to help it breath this motor is tuned port injection, i havent had any problems with it. So i guess if you build it right you can have a strong lil motor that pulls up to about 5500 with about 370 horsepower!!!!!!!!!

Code1racing

Cool Thanks for all the info, I've been out for a while and the car is still down at the moment, but im happy to be back Im going to do some DIY head work get my exhaust & everything else properly set up on this car. Hopefully I can have her complete sometime by this summer or fall to take her back to the track.

64elko

GOOD TOPIC
I JUST INSTALLED A 1979 -010 HIGH NICKLE BLOCK 350 TPI WITH 1986 305 HEADS 1.94 /1.60 VALVES,, Flat tapit cam,compression is 10.1, There was some porting on the heads but i don't know how much. I am running 87 octane an it is running good this is all in my 64 ELKO... it just has 50 miles on it TODAY.. i got on it a littLe hard yesterday an it was pulling the left side of my elko off the ground,,,,,
So yes 305 heads work with the 350 block with the right work do to them..I have stock exuest that are duels all the way out to the back bumper. (HEADERS SOON )
Now i got this motor as a long block from a local builder..( Tacoma washington ).. i just put it in an put on my tpi,,,, plug and play......all for under 2 G'S ....

jamienoel

Mine has 305 heads.

It runs ok and seems fine with 87 octane.

I have a couple minor bugs to work out.

Code1racing

Hi guys, sorry I havent been replying to any of your responses, I had to immediately leave to go to basic training, & 5 months of tech school afterwards. Im able to start back on my car now. The heads were ported out as much as they could be, & now were taking them to someone to install the valves & the guides. As far as getting the car running Ill have to wait until I have enough to order a bowtie overdrive 700r4 stage 3 trans.

RodsRideSS

Yes...World S/R Torqer305 heads. Check them out on the web site. I bought them for my 305 and a couple of years later, I installed them on my 350. These are excellent heads! I polished, ported and port matched them first. These have bigger valves, flow better than the stock 305 head, 58cc, 180cc runner I think. The 350 is the L31 GM from the vortec years has a slightly dished piston which works out to 10:1. Also...the heads are centerbolt valve covers!

Westech

I was going to do trick flow heads but i found a set of 187's with 202 SS valves for 500 all redone. I want to keep the stock look (less headers) on my car. I think with 202 and valves, dished pistons and a .030 (give or take, need to find out how far down the piston is) head gasket to get in the high 9's CR I should be good. I have built a few 350 dished 305 headed engines with .015 shims and the engines were great low and mid.. pulled really well but started to run out at 5500. With larger valves and a good cam there no reason why it wont be a great engine to pull a heavy camaro around. I think for us DD's and street guys a 5000 or so upper RPM limit is perfect.

1gary

This is a ying-yang approach.

Run 10.5 c/r on cast pistons with cast iron heads??.

So you add c/r one point above where it should be with cast iron heads and then take it back away with ignition timing or cam timing.And for what net gain??.

Then you say he has to run premium gas knowing full well there isn't a standardization of pumped gas anywhere. So what is he to do??. Buy 114 race gas all the time$$$$??. Oh,I know your answer already. He could mix race gas and pump gas.Right??. We both know someone who was doing that and it worked until he got the mix wrong and blew-up some pistons.Who might that be??. Opps,it was you.

So your suggesting he mess around with 305 heads both of us knowing in the end no matter what,they raise the c/r beyond the gold standard of 9.5 with cast heads and don't flow well.Ported or not.Why?. Just because of a bragging rights of a cast iron head run at 10.5??. Then having to compensate for it everywhere else. Then you talk about matching up parts with the cam he has and here again both of us knowing full well that cam needs compression to work and flow. Sounds like a band-aid fix to the wrong cam with tons of effort on heads that ant right in the first place.

All of this when all he has to do is wait alittle longer to buy aftermarket cast iron heads that would be correct for his cam to complete his combo. Actually in the end might work out to be cheaper with much better results.

Clearly the MSG here should be with SBC's a bulk of the money needs to be spent on cam and heads on a sound bottom end.That there isn't any real cheap answers for that. And never will be.

In terms of you F-Bird.If the msg is confused,then so is the messager(sp).

1gary

Oh,one last thing for all of you to read and heed. The idea of home hand porting is a unverified caveman well,well,years past it's prime approach.No flow bench numbers to compare and no comparison to the aftermarket heads that are pretty dam cheap these days. The sad truth is when you hand port,you just don't know what your missing. And do-overs cost money when you finally decide to take off your now over priced hand ported heads and buy the aftermarket heads you needed in the first place. The big "O" factor then comes into play..........................

cuisinartvette

Well said Gary.

Sucks but you found out the truth about those heads.

Its simply not worth the time and money putting larger valves porting etc etc into factory heads. They still dont flow worth a hill of beans.

If you want to experiment and simply have NO money for other heads go for it.
Weve all been young and broke once or twice and had to do it
Just dont expect much.

Otherwise throw the factory heads in the trash where they belong.

bygddy

Gary isn't a big fan of anything that isn't the latest greatest wizz bang big dollar part....he knows his sht, but plays with a vastly different budget then the rest of most of us. So its hard to relate to some of his advice and opinions....if I had lots of cash, and want to go fast, sure, I will gladly listen to his advice and be happy with most of his recomendations. All that being said, the 416 heads, when done right, are an excellent budget build choice....assuming your not spending big money. I did a set with 194's and many hours of home porting, very little cash spent on them. Went on a stone stock 350 with a 1094 gasket, a small lunati barebones cam, terrible Shorty headers to sidepipes, a performer intake, and a lowely Qjet, shouldn't be fast, should ping all the time, run out of steam at 4500rpm....yah, that didn't happen, I have had a couple fast cars, and been in many....this flat out hauled. Shocked absolutely everyone, pulled hard to 6k, got decent mileage even with 411's. And never pinged, never hurt itself and I'm not gentle on my junk, sold it, new owner has had it out twice (finding dry days in winter sucks) and run his buddies malibu wagon with it.....355, air gap, comp 268, 650DP, t5 and 411's. My little 416 headed vette he bought tore the wagon apart to well over anything close to legal speeds. The wagon is quick, I know this cause it was also mine. In a nutshell, you get out what you put in, spend the time porting them as best you can. Match the rest of the combo right, and you would be very surprised at the result. Rant over

bygddy

Felpro 1094 gasket, 0.025 in the hole, 61cc's, stock 4v pistons, puts me at 10.4 . 18 initial, 38 total, dead heat of summer runs mint on ultra 94, used 92 many times in a pinch, no ping, no melted anything, no crutching with reduced timing. Sorry, but it can be done. No disrespect intended, but is it something u have tried personally or just internet hearsay? Because I doubted it, but had the parts, and the time, and it flat out worked.

Fast355

iTrader: (2)

I had a true 10.5:1 static compression ratio on an iron vortec head 383 in my old G20 that ran fine all day long on 93 octane with a full 32* of timing advance.

As for 52cc 305 heads on a 350, even with a tiny RV cam and 230 psi of cranking compression, I ran on 93 octane with 34* total advance. It pulled a 5,300 lbs G20 deep into the 9s in the 1/8, but fell off as the brick like aerodynamics of the van became apparant.

bygddy

Good quench is a beautiful thing...

bygddy

Your "hand porting is stupid" theory is flat out retarted....you like to spend money, go get a set of AFR 195's and a set of Pro-filers that have been lightly breathed on by Chad....then try and tell me hand porting is archaic.....oh and with the 300-400$ you save on Chads heads you can buy us a round of "sorry I was wrong guys" beers.

InfernalVortex

iTrader: (4)

Im hardly 1gary's favorite cheerleader, but a professional guy like Chad Speier who gets to play around with actual flowbenches while he ports and has a LOT of experience is a FAR FAR cry from some yokel in his garage with a dremel.

1gary

I HAVE JUST NOW COME TO REALIZE THIS USER IS SURFING MY USER NAME BETWEEN TWO FORUMS WHICH SEEMS TO BE FOR THE SOLE PURPOSE TO BE ARGUMENTATIVE.AT FIRST I THOUGHT HE WAS LOOKING FOR MY ANSWERS TO HIS QUESTIONS AND WAS THE REASON WHY I REPLIED.

I WILL NO LONGER REPLY TO HIS INQUIRIES.

I DO THINK THERE IS SOME SORT OF RULING ABOUT THAT KIND OF ACTIVITY ON BOTH FORUMS!!!.

I DON'T THINK HE CAN BE TRUSTED TO ADD ANY VALUE TO ANY THREAD.

THEREFORE NEEDED TO BE EXPOSED ON THE OPEN FORUM.

bygddy

Wow, your panties really are in a bunch eh? Hey Gary....take a Valium and relax....
Have you home ported a set of 416 heads and tried them before telling people they are stupid and a waste of time? I simply remarked that for all appearances it seems like you have a vastly different view on "budget" and there are more then one option to go fast....same argument I have had with you elsewhere...im not chasing you around forums, I'm sure your a good looking guy and all that, but I suspect we couldn't date due to my beer and crackers budget....I would just dissapoint you.....sorry guy. I did however come into a thread titled HAS ANYONE EVER TRIED 305 HEADS ON A 350...!! And yet again, here you are, in a thread not relative to anything you do or are doing with your 786 CI 9034hp alky motors.....wait, are you chasing me? Now I want to complain, where are the GD internet police...? Dude, fkn relax, its a forum.....where people have opinions, about the same subject....and here we are....and I actually own a third Gen F-body, and have done 305 heads a few times now....so really, why are you and your yellow 383 mini van in here arguing?

DeltaElite121

That's like telling someone they can draw the Mona Lisa with crayons. Is there that occasional person that can do the extraordinary with what they have? Sure. HOWEVER - 95% of the population can't, and end up making things worse for themselves. Obviously, the technology had to come from somewhere and people have been going fast with limited means for over 50 years now. Chad Speier has been in the game a long time, and he's one of the 5% that know what they're doing very well. He's the exception to the rule.

Porting cylinder heads isn't a waste, but dumping money into a set of doorstops is with how many viable options are available these days. I ALMOST made that mistake when I was new. Glad I didn't listen and saved my money... because otherwise I'd have a boatload of money into something with nothing to show for it. Might as well just light your money on fire at that point.

bygddy

I have to respectfully disagree, if Davinci didn't pick up that crayon, the Mona Lisa wouldn't have been painted. If Chad hadn't picked up that die grinder, he wouldn't be where he is now. Nobody said to go buy a set of 882's and hack the fk out of them. They are garbage stock, and likely worse cut up by some kid with a cutting bit. But were talking about 305 heads for crying out loud, that can be had for couch change. And you have to start somewhere.....I took a set, and spent a bunch of time reading, and learning as much as I could, then I went to town on them. My pile of junk vette went 16.20's stock according to a g-tec, then I installed a tiny lunati cam, Shorty headers, and a performer intake, and yes my junk, home ported 416 heads, NO OTHER CHANGES.....g-tec said high 12's.....nope, nobody is arguing about the accuracy...or non accuracy of a g-tec.....but a 3 and a half second gain.....for couch change, and some time...seems pretty substantial....and I beat it, hard, daily.....overheated it a few times, over revved it many times, and its still running, and still quick as hell......can I port heads? Jesus no...I'm a hack at best.....but I read everything I could, and tried, my machinist liked my first set, and loved the last 2 I did....as did my buddies using them....i didn't charge anything, cause its fun, trying to shape, see where I can make improvements, its neat. Would I cut a "good" set of heads....for someone else, no way...for me....maybe....but I'm an idiot sometimes.....my point is, everyone starts somewhere, and what better place then a set of junk heads that most people disregard, and on a budget and just want to be reasonably quick.....we all started somewhere....and unless your born with a silver spoon in your mouth, it wasn't with AFR heads.

1gary

quote=bygddy;5506391]Wow, your panties really are in a bunch eh? Hey Gary....take a Valium and relax....
Have you home ported a set of 416 heads and tried them before telling people they are stupid and a waste of time? I simply remarked that for all appearances it seems like you have a vastly different view on "budget" and there are more then one option to go fast....same argument I have had with you elsewhere...im not chasing you around forums, I'm sure your a good looking guy and all that, but I suspect we couldn't date due to my beer and crackers budget....I would just dissapoint you.....sorry guy. I did however come into a thread titled HAS ANYONE EVER TRIED 305 HEADS ON A 350...!! And yet again, here you are, in a thread not relative to anything you do or are doing with your 786 CI 9034hp alky motors.....wait, are you chasing me? Now I want to complain, where are the GD internet police...? Dude, fkn relax, its a forum.....where people have opinions, about the same subject....and here we are....and I actually own a third Gen F-body, and have done 305 heads a few times now....so really, why are you and your yellow 383 mini van in here arguing?[/quote]

bygddy

[/QUOTE]
Yah yah.....you want me banned.....because you acting like an insecure old fart....relax man, I'm not interested in playing fun little internet war with you....its pointless, like I said before, everyone has an opinion....and some are even valuable, which yours are frequently, in this particular thread, where the OP asked a question, that i had first hand knowledge of, I answered, you of course touted another, more expensive route, hell maybe im wrong and the op has lots of cash or experience and your ways right....if so, I stand corrected and apologize....imdont suspect that's the case....but really, your taking a **** fit and calling me an interweb stalker lol....so I may as well yet again, as I have before, apologize to you for nothing....and agree to disagree

1gary

What we have found in our engine building business is it is true the 305 heads do raise SCR's,but don't flow worth diddle.That confirmed shapes from a flow bench is the only thing that"marginally" improves them.From a flow bench and from someone with yrs of experience porting that is with knowledge of A/F dynamics.

I totally agree with you Delta.Our R&D confirmed to just open up a space with a die grinder does in fact do more harm than good.

And once more,cam/SCR comparability along with quench are critical elements for performance of today's pump gas engines.

Our answer to this question from been there done that,corrected the mistake,is no I do not advise the use of 305 heads on 350 engines.

bygddy

And from personal experience, without a fancy r&d department, they can be made to work well. See? Simple polite dissagreement. One guy claimes Mega bucks research, and another has actually built an engine that does exactly what it was intended to do. I shall bow out gracefully now. Thank you for your time.

Westech

I have built 3 other 350 Roller engines with 305 187 heads. Two stock small valves and this one with the larger 202 160. I will be dynoing (sp) This 3rd engine. I was happy with the power the other two engines made. could I have made more with different heads? you bet! But there has to be reason with every build. If everyone's end goal was to have the most high out put engine on earth there would only be one block, one set of heads and one cam shaft on the market. But there are 1000's of different parts to choose from. You have to remember for a lot of us most of the fun is doing it our self's and just tinkering. Figuring things out from what we can learn and what we do.
If you ask a question you will get 100 different good answers. Take a little here and a little there.
But I dont and wont take any one persons word as the gospel. Thats how trouble starts.
End point.... I have installed 305 heads on a 350 with .015 gaskets and ran on the street. She did get a touch warm but it was a blast to drive. Would roast the tires right off the rims.
Now would some other car beat me in the 1/4? ahhh yeah but I was happy with what I built for a few bucks.

1gary

What I do is apply my background of been there done that to prevent people with limited funds from losing it all on poor advise.The guy who came on here and didn't know it was that advise that lead to a blow-up and is too embarrassed to post here again of what happened thinking it was his fault.Usually on those kind of losses they never return to cars,hot rodding,and can't recover from it.

Westech

O i have done my share of oops's. Did not break in a cam right and is was a lifter wiper. we all been there done that. If you only have enough money to build it once I would stick with OEM stock or keep to the cars that snap or glue together. (less sniffing the glue) I am in to Military trucks big time also and you want to see some money out the window.... check them out. its a hobby. if you live or die by it you need to change your out look or just do something else.

WolfmanTA

Hi Bro! Put 305 heads on a 350 in a 76 Nova I had. It went like hell. Was a nice ride till too many brake stands ripped the front of the leaf springs out of the floor. Dam unibody frames. LOL... Cheers Bro...

Atilla the Fun

Nobody is an expert on everything, but we have a few legit experts on here, each of whom can be relied on, in their individual fields of expertise. And yes, I am one of them. I claim it, and I keep proving it. I have peers here whose word I feel comfortable believing even when everyone contradicts them. Thing is, it's natural to believe those whose experiences matches, but that doesn't make contradictory postings invalid by itself. When you don't know what to believe, ask the moderators who they believe, and why. But taking a little from everyone? Too many chefs ruins the soup. I'm not believing you did 2.02" valves to 187 heads until we see proof. 1.94" valves on '081 heads isn't bad, but isn't great, either. Gary's way wrong saying 416s won't get a 350 to pull past 4000. 416s flow within 10% of most 1.94"-valved 882s, 624s, 487s, et cetera. Maybe gary had a bad HEI module, or spring surge, or an LG4 cam? Who knows? But you don't need big valves and porting to get the better 305 heads to make a 350 pull strongly through 5000 RPM. Just don't get crazy with the cam specs. For '081s or '416s on a dished-piston 350, look at Comp's XE262H10. NOT the XE268H10, these heads don't flow well enough to support that, you lose more low-end than you gain at higher RPM. Ideally, look at 0.500"-lift HR cams when putting 305 heads on a 350. Comp's Magnum 270 is a good choice.