i am looking to build up my 305 because i dont feel like buying a new eignie, this one fits fine. so i need heads, i thought about vortech heads, dart heads and someone told me that airflow research has some good heads, but i want to know, if anybody could help me, which heads would be best for a 305?? when im done i want to make just a tad over 300hp. can anybody please help me.

 

Your best bet might be getting a set of 305 heads off a thirdgen 416 casting, and following SittingBull's sig directions on how to port them.

You'll need a low cc head to maintain your compression on that 305.

 

what exactly is a low cc?? number wise. just using 305 heads will be able to make good hp?

 

No, but port and polish your current heads by following the link at the end of my sig. Also, just copy my whole engine if you want 300 hp.

 

mister bull,
i was thinking of going with the edlebrock tes headers, do you think the hookers would be better?? im not sure what the "416 castings" means but is that the stock heads on my stuff?? is there anyway to find out? because its not the stock engine, it was replaced in 98 or 99. also what did you do to your qjet?

 

you need a head that has a combustion chamber size equal to 58cc or lower (52cc, etc.). DO NOT USE 350 HEADS, it could be a bad thing.

 

I don't think there is much difference between headers, personally, as long as they use the same size primaries. For a 300 hp 305 I'd use 1 5/8" primaries.

Your LG4 305 has 416 heads, in all likelihood. They came on all carbed 305s in thirdgens. 416 refers to the last three digits in the casting number on top of the head. 081 and 601 castings are good too.

For the QJet, go to the Tech Articles and read up on the columns dealing with it. Basically, adjusting the AV spring tension and installing a B hanger with DR rods.

Good luck!

 

Other than porting, for performance the factory heads need 1.94" intake valves installed, better valve springs, and the press-in rocker studs replaced with screw-in studs. This can all be done, but will cost you time and money to accomplish. If they have many miles on them, the guides may also be worn and in need of replacement.

With factory heads, you're also taking two other risks: Cracks and core shift. Cracks can be welded (usually), but again more time and money. Core shift will mean your porting work may all go down the drain when you hit water or oil while trying to clean up a flow path.

In the end, it's my opinion that your best bet is to get a set of World Products S/R Torquer 305 heads. They have the correct 58cc chambers, screw-in studs, 1.94"/1.50" valves, good springs, all in high-quality castings. The only nit to them is that they really need at least a pocket porting to get the performance out of them. The best source for them that I found was Competition Products. It's quite possible to actually spend less money on these new heads than on improving the factory heads you have now.

As for headers, I can say the Hookers are good. From what I've heard of TES and Hedman, they have weak points that the Hookers don't. The y-pipe of the Hooker 2055s is especially high quality.

According to the MPH -> HP formula in the latest Hot Rod magazine, I'm putting out around 250 HP at the wheels. That ain't too shabby for a 150k miles 305 shortblock in an emissions-legal package, in my opinion.

 

Tim,

I think you are over-dramatising the possibilities. For a mid- to mild-305 (or any other size) the heads are very likely to be perfectly fine.

 

Well, not to start a shootin' war here, but the stated goal of "just a tad over 300hp" isn't exactly a mild 305. A pretty healthy cam will be required, which needs the larger valves, full porting, and upgraded springs to get there, and screw-in studs for longevity. If the guides are at all shakey, you don't want to put the heads together and sacrifice power and longevity to the gods of cost savings.

And, my statements are pretty mild compared to the drama of the moment when you break through the wall of a core-shifted port casting. Granted, may not happen to everybody, but if it happens to you, you've just lost the investment of the machine/porting work you've already spent on the heads you've now taken off your previously-running engine.

Add up the costs of doing factory 305 heads (these are off-the-top-of-the-head prices, not recent quotes and therefore probably low):
Tanking: $35
Rough-in 1.94" intake valve seats: ~$10/cyl, $80
Remove press-in studs, machine for screw-in: $50
Replace guides (if needed - most likely is): $75
New intake valves: $50-$80 depending on what you get (double that if exhaust valves are worn)
Rocker studs: $20
Valve springs: $30-$75
Seals (might as well make them positive-sealing type while we're at it): $15
3-angle valve job and assembly: $150

That's $500 minimum, and doesn't include the porting, or shaving (in case there's some warpage), or crack repair. I realize the price has gone up a little, but I got my unassembled heads with all the pieces for under $600 shipped. Considering the Worlds are much better castings, and that the port and chamber shapes make for better flow and combustion, I'd say that's a hundred bucks well spent.

 

Well, I just had all that stuff done to mine a couple months back and it came to less than $400 US. If your cam is .46x lift or less there is no need for screw in studs, or you can pin them much cheaper.

If you do your porting prior to machining you will have no grief from a core shifted break through, and that is pretty rare anyway. And if you do, another head is cheap at the wrecker's.

Or you could get a set already done from F-Bird'88 for $375 US + shipping. Can't beat that with a stick

 

Isn't it amazing how you can juggle the numbers to suite your point of view on a subject.
Try these real world #'s on for size
First completely port the heads, yourself. Do not take them in to have the 1.94 valve seat "roughed in" and then pay for it to be done again. Waste of money.
Just port them out to just a little bit smaller than the stock 1.84" valve seat. It will be just right now for a new 1.94x1.60" 3 angle valve job. Screwin studs are unnessessary for most street jobs.
Excessive valve spring pressures or cam lift or rpm are not called for here.
You can drill and "pin the studs" your self for $12 including the drill bits. Done...
You can buy a set of 16 budget 1.94x 1.60valves for $100/$125
Now scrub your ported and pinned heads yourself with oven cleaner and lots of soap and water, till they're spotless before you take 'em in for machining.
Unless your guides are real worn out, just have them knurled
to tighten up the clearance. Ya don't want it real tight either
or the valve will grab and hang under heavy full throttle use. ( Heat).
I did a set of BB chev heads this way and they lasted 10+ yrs.
Now have them machined. 3 angle valve job, shortened guide
boss for positive seals and high lift. Have 'em shaved a little only if
they need it. Tell the shop to not bother cleaning them either.
Take 'em home and scrub 'em with more soap and water.
If you take 'em in clean, they will be basicly clean when you get them back with just some metal chips from machining.

Wipe 'em down with Rust Check.
Now assemble them yourself with new valves, seals shims, springs etc. You'll even be able to afford the spring compressor rental.

Why pay a shop to wash and assemble your heads when you can do it yourself.
This is how you budget prep a set of street/strip 305 heads
for very reasonable money$$$.
Do another set for your friends and make some $money.$

Here is a complete head improvement kit for $130us. + shipping.
Includes 1.94x 1.60 valves, hi perf springs, locks,retainers,seals.
Competition Products PN#851296
Now you need shims. Available in .015,.030,.060" @.039/per
You need a stck of 3 shims (.015,.030,.060") for each of 8 exhaust valve seats. Use spring shields (.030") over for the intake side. Thats all you need to do. 1.73/1.75" installed height.
www.competitionproducts.com

Not that hard to do. Not that expensive either.
Ya just got to do all dirty work yourself. But you'll have the satisfaction of building your own set of heads that can/will outperform many out of the box, aftermarket heads and for less.
$Doe$
As long as you don't mind doing a little dirty work yourself,
there are millions of good 305 performance HO/TPI heads available for a song that are just right for a mild /moderate street/ strip 305 or 350 upgrade. Many times you can buy a whole running 305 motor for less than $100.
Unless you're $Howard Hugh$ this should be a no brainer.

 

I'm sure most people out there, like me, have their projects come out at or below the going-in budget...

Hey, at least nobody has gone down the Vortec/Dart/AFR-on-a-305 route.

I think we can agree that there is more than one way to skin a 305 mouse (how's that for a twisted metaphor?). Personally, I was trying to balance cost, performance, and down-time, since this is my daily driver. As is always the case, you have to weigh the pros and cons of each option yourself to determine your course.

Who knows what heads are on that "replaced in 98 or 99" engine? But, like said, 416 heads can be had (I'll let mine go for the cost of shipping - they do need guide work, and knurling probably won't do it). Would allow you to get them ready while still being able to drive the car as long as possible.

 

Here is a copy of my machine shop bill for all the work on the heads.

On top of this would be the $40 for carbide cutters, $48 to rent a die grinder and $30 to build a speed control unit. Add another $25 for some wrecking yard heads.

sub total = $532 Canadian, or about $340 US.

They knocked $80 off for my two week wait, so let's add it in just to be accurate.

Total = $612 Canadian, or about $390 US.

You can't find another set of good performance heads for anything close to that, I'm sure :hail:

 

Thought I'd give this a rest overnight and let it cool off. Also gave me a chance to think it all over during my 5-mile run this morning

Allow me to summarize:

Cost Without a doubt, factory heads will be less, even if you have to go through half a dozen heads to get a workable pair. Advantage - factory.

Quality Worlds are aftermarket-quality castings, with thicker decks and more material where it's needed. Chance of core shift next to nil. Likelihood of cracking much reduced. Advantage - Worlds.

Time The Worlds will be clean as-received; the amount of material needing removal will be less; casting flash is less; don't need to alter valve sizes, rocker studs or guides, etc. For example, I spent 2 hours practicing on one cylinder of a factory head, but finished off the Worlds in just 8 more hours. Of course, I did each step to all 8 of the Worlds at one time, saving some set-up time (although worn-out roll replacement ate up some of that), but there is no doubt that the Worlds were easier to port and polish than the factory head was. So: Advantage - Worlds.

Final product The Worlds have better chamber shape, better port shape. Raw flow data does not tell the whole story, as how the flow enters and exits the cylinders will affect torque curve and peak power. Valve shrouding is a problem with factory chambers, and when you add larger valves, it only gets worse. Unshrouding the valves adds chamber volume, decreasing compression. I don't know of any aftermarket suppliers making 305-specific head gaskets anymore, so you are stuck with 350 gaskets - World specifically warns not to use 305 gaskets with their heads, rather use 350 gaskets to take advantage of the reshaped chamber (making the 350 gasket actually work better with them than they would with factory heads). Worlds also have more meat where needed to avoid hitting water or oil. Worlds have more material in the spring seat area so upgrading to larger diameter springs is less risky. In the only back-to-back test I've seen, pocket-ported Worlds made 50 HP more than 3-angle valve-job 416's (would have been nice if they treated both to a full SA porting job, 3-angle valve-job, and ran them again). Conclusion: Advantage - Worlds.

It wouldn't be fair to just add up which has more "advantages" in the above - who can say if time is more valuable to you than out-of-pocket expense? Only the person making the decision can factor each area, so each of us has to do that for ourselves.

You are saying I'm overstating risk and cost. I'll say I think you are understating risk (just because you didn't have cracks or core shift doesn't mean plenty of others haven't been bit by it). You're also understating the ease of working over factory heads. I'd also argue that you're overstating the power potential of factory heads (although for a 300 hp build-up, that may be a wash).

I won't claim that I thought this all through thoroughly before getting the Worlds. I never seriously considered using factory heads, just because I assumed the final product would be better with the Worlds. I've since warmed up somewhat to the case for using ported factory heads, but nothing I've seen has convinced me that my original decision was wrong.

I promise this is the last I'll say on this, unless someone asks me specific questions.

Peace and prosperity.

 

Tim,

Can you post a pic of your combustion chambers? The only World 305 chambers I've seen were the ones they used in the CHP My Generation Camaro, and they looked just like a 416 chamber, IIRC.

Time-wise, your World's will beat the heck out of doing it yourself--hands down! Without question, you are looking at 20 or 30 hours of intensive work with a grinder. But, overall, I must confess that I enjoyed my hands-on experience with the heads. When I drive my Camaro now I have a sense of pleasure knowing that part of its power is due to my own two hands carving it out of cast iron

Quality is a subjective thing, in as much as "What do you want, after all?" Does the factory casting serve its purpose properly? The answer is yes.

Flow=Power, no two ways about it. Chamber shape is important but I don't think it will amount to something like 10 hp or anything. So I don't see how I'm overstating their potential.

As to danger from casting shift, I don't know what percentage of factory heads would sufffer from this. I've only done my own set, which had been rebuilt twice before. Perhaps F-Bird'88 could chime in here and let us know how many he's broken through on.

Feel free to disagree

 

Well we had nothing to do today so we fired up the flow bench again.

Remember the void in the roof of the port where
the stud comes thru? We tested my heads with and without puddy filling the void. Result +6cfm.
Tested the heads with a manifold attached.
This gives a more accurate guide to the power potential of the motor because your testing the whole induction system
as a system.

305 heads+ vic Jr. 228cfm
305 heads + holley strip dominator 225 cfm
305 heads + wieand 7547 210 cfm.

The strip dominator is what I have so that what I'm going
to use. looks like 110mph potential. (370 rearwheel hp)
My car or motor is not perfect so I'd fudge that figure back to
107mph (334 rear wheel hp). Too bad we'll have to wait till spring to find out what she'll do.

Sitting Bull: 57 will never be convinced otherwise
because that would mean he made the wrong choice.
But the real fact glares ya right in the face.
His car goes 92 mph in the quarter (97mph corrected to sea level) *his correction factor, not mine* with the S/R heads.
You're at a high altltude too and otherwise have a very simular car combination. A fair comparison would be to compare quarter mile performance of your two cars.

 

Yes, it would be an interesting race!

So Tim, come on up to Cowtown and we'll have at 'er out at Race City

Actually, it would be a downhill drive from Denver, wouldn't it?

 

Isn't that interesting! I remember in that "How To Port Vortec Heads" article I emailed you that they found no increase in flow by filling in that cavity on the Vortecs. It must be casting series specific, eh?

 

This viod on the vortec ports is only a little indent.
The one in the 416 head is huge.

 

So, is a big dollop of JB Weld the answer?

 

Well it wouldn't be my first choice.
JB Weld tends to turn soft in gasoline. (I've heard this. Not personal experience.)

I would use POR15 Epoxy Putty.

Actually I don't think I'm going to bother.
I had more variance between all the ports I tested.
head A set 2: 243 cfm

head A set 3: 239
Head B set 3: 231 and 237 with the void filled.

All these are better than the results that a guy got with 041 camel backs with 2.02's (he does this for a living also) {I don't)
All of them are way better than stock or S/R heads.
All if them are better than I ever expected.
Me and my friend also tested a set of 920 casting that another friend did. ( it's a first attempt for him and he's not that inclined
to this. Or confident.)
His head flowed just as good as mine.
This proves that anyone can do this with minimum instruction
and experience. Ya don't have to pay someone to do this.
It just takes effort and time.

 

F-BIRD'88

I'm assuming that your flow numbers are at 28 inches H20.

At what valve lift are you performing your flow tests?

 

Didn't have digital camera at the time, took some 35mm's, the flash didn't sync properly, so only got half a frame. But, the overall shape is closer to your heads but valves less shrouded, no spark plug boss sticking into chamber like 416's. The other differences are more subtle.

I hope that is never true of me. I get so sick of hearing import owners brag about their cars, which must be so good since they bought one. No, I certainly made mistakes in what I've done, and am willing to admit it (non-coated headers, universal Catco cat instead of direct-fit, etc.). Just not in this case...

Hey, I did say "I've since warmed up somewhat to the case for using ported factory heads", didn't I? Give me a little credit.

Forgot to mention it above, Worlds don't have that little flow interupter.

Actually, it's NHRA's correction factor, applied for elevation only, not density altitude (the '57 ran .1 sec and 1 mph faster in Topeka than the correction factor said it would). The sig also says "w/o 2-3 shift", which means I go through the traps in 2nd at about 500 rpms over the peak power. I've only had the car out twice, once in early May and once in late August, and have done absolutely no tweaking. Perhaps next winter I'll be able to get the tranny up to snuff (works fine for daily driving), get a rear with some gears in it, and have it ready when my son turns 16 for high school drags. Until then, I consider the current numbers to be baseline only.

Would have been nice to get flow #'s on the heads after they were finished. All I have to go on is Worlds' claim of 213 as-delivered, and SA's statement that following their process will yield a conservative 10% improvement. Plugging those numbers into DD2000 along with other engine specs, and plugging the results into Dragstrip Simulator, produces 14.4's runs - reasonably close to demonstrated (corrected) considering the handicaps. Sure, this paragraph contains a lot of guestimates, this is all about bench racing anyway, right?

Along that line, had I ported my factory heads instead of buying Worlds, I could have afforded coated headers. The performance improvement from ceramic coating may be more than the difference of ported Worlds over ported factory heads. Maybe. Maybe not. But, the car would have been down for about 3 weeks instead of one. Meaning driving the '57 to work for 3 weeks in November in Colorado...

luvrgodd, sure hope you're taking notes. No doubt this has gone way beyond what you expected when you asked.

Wouldn't we all just be better off if all other head designs went away, and the only thing available was Vortecs?????

 

Several guys, including me, have used JB Weld to seal the well plugs on the bottom of q-jet bowls. The stuff doesn't have any problem in gasoline. I also used it to plug a porous runner casting on the factory 396 intake manifold, where it was exposed to gasoline on one side and oil on the other - was still fine a year later when I put the Weiand on.

 

I Would like to Add, that Sitting Bull And F-bird's Claims and Peak Flow #'s are all fine and Dandy...

But Neither of them Has Any 1/4 Mile or Dyno #'s to Back them Up.

You might be surprised at what you find

 

Yes they are flowed at 28"

I don't know what valve lift they are flowed at because the
valve lift fixture is not on the bench.

This is just a very quick (free) check of the max peak flow and what ever lift this happens to fall under. I just opened the valve and adjusted the airflow of the bench to get the max flow at 28".

Stock heads typically "stall out" at .550" lift meaning they
don't flow any more or slighly less above this figure.
We've found this to be true of must of the (stock ) heads like this
reguardless of what you do to them. These heads typically exibit good flow at ..400.450,.500" too meaning if you got a good peak # the head will be good else where too. Resulting in good overall performance. Even the very low lift #'s are nicely improved over stock. So while the peak #'s don't tell the whole story
they are a valid indicator of the overall performance of the port.

 

This is true but they are coming. I also have flow numbers
on the vortecs that are on the car and quarter mile #'s
the vortecs flowed 228 @28" and the car runs 13.05 @104 best.
The average times are right around 13.3 @103
The traction on a Fri night Test 'n Tune can be a challenge

when the *****'s dump antifreeze and trans fluid all the time...

The ported 305 head are out flowing the vortecs.
They aren't going to run any slower.

I've also have years of experience, tuning and tweeking a combination at the track, You may be suprised what I find.

 

GTECH it?
I have one just laying around.

 

I'll say this much; F-Bird'88 sure has a lot of our cousins in the lower 48 awfully worried that $400 will get you what they paid a lot more for

 

I have a new engine goiung in in january and i curently am running a 350tpi if you want my heads they are in good shape and my engine runs great no smoke but of course i need more power anyway you can have them for 300.00 if you want email me at rick3rc@cs.com im also a senior member here so look me up.

 

yeah thats what im doin

 

This will give you some idea of what the cam and heads add to a 305 that has all the other parts already there, i.e., headers, intake, etc.

DD2000 isn't 100% accurate and you should knock off 20 hp due to its overly generous estimation of power from an average dual plane intake. But, overall, I think this type of 305 will be right on to 300 hp if put on a dyno. And that is mid-14s in the quarter mile :hail:

 

I used JB weld on a stripped out hole on the front of my engine. I just basically just jammed a setscrew in it, and puttied over the hole.

Has no problem with oil....worked like a charm.

 

It's not good advise to tell someone they can clean there own metal particules out of there heads. Contamination of the worst kind could knock out brgs quickly and kill a motor if done wrong. If the person asking the question was proficient enough to know what to do they wouldn't be here asking the questions.

You can't possibly believe that the 305 heads are the best head choice for a small block Chevrolet cause there not. Not unless all the pro's out there missed the fact that 305 heads flow better than anything else. Why is the fast most powerfull small blocks running everything other than 305 heads. Think about where your heading with you car and how you want it to run. Study, invest and learn in what you want. Save for that and spend your money there.
Heads that flow in the lower lift areas with greater amounts will indeed run better on the street.
Valves spend most of the time at the halfway point of the lift and thats important to note when you get a set of heads, cylinder heads will poor enough air in at full lift to work with most combinations I see here. You gotta be able to flow the cfm's to use them at max lift. which will mean more money. Porting cylinder heads is a plus regardless of what they are but it's a lot of work and money spent for something you will want to replace later.

 

Can't help it if you don't believe it, dude. But might I suggest you TRY it before dismissing it out of hand?

 

90Formula:
You've never done this. I can tell. Thats ok we're not born
with knowledge.
Yes, you can clean your own heads. Better than the machine shop
will do. I do it all the time. I recommend you do the same.
Rub a clean rag on your heads ya just unreapped from the machine shop and you'll know why.

No 305 heads are not the biggest, baddest most wonderfull
smallblock head.
In stock form they flow less than just about all the 350 heads.
Why, because they have smaller valves and rough ports. Don't be an idiot. The basic good port shape is there you just have to tweek it and clean em up.

You find him a better heads that will flow these numbers below
for $350/370 complete. Or less.
Be very carefull to "study the low and mid lift#'s" and then go open up all your hotrod books and surf the net to no end
and find those heads.
Then make sure the fit a 305. And report back to the origional poster. Cause he and I would like to buy them.
In fact I'll double your budget. to $700
Now here are the numbers:

@28" H2O intake

lift
.100 70.1
.150 105.2
.200 135.27
.250 158.6
.300 187.0
.350 205.41
.400 222.11
.450 225.45
..500 225.45
.550 218.77

"The Pro's" Like Every Street Stock builder in North America
are well aware of the potential of these 305 heads.
Thats why most circle tracks ban them in the lower stock head classes. Why, cause they make too much power with them.!!
What heads do you think "The Pros" use to start building a
NHRA LeGAL super stock motor?
Survey Says:! A friccin' stock head..!!!
On a 305 that means a 305 head. And they have to use the stock 1.84x1.50 valve size.
In order to go 10.99 et in the quarter mile in a Monte Carlo
ya have to be makin some power. Hope and good wishes
and a strong tail wind will not help ya.
Thats what a NHRA superstock 305 Monte Carlo runs in the quarter.
Jeese do ya think that will be enough head for our buddy???
to get 300+ hp. I think so.

Please, give it a break ..... Have a nice day....

 

 

i have a set of the 350 heads i will sell cheap if you guys are interested im surte you will get plenty of horse out of them with some porting and bigger valves they are off a 350 tpi.

 

Did someone say comparison?


416 - 187 - World

416 - 187 - World



Yeah they were sittin outside for awhile

I'd say you're better off starting with the Worlds. Just MO.

 

At least clean them up before comparing them! Everyone is going to think a clean shiney head is better than one that needs a dip in the bath!

What difference do you see now?

This is a 601 casting.

 

Looks different from my 416 casting.

 

And now?

 

Well, it's clean for a start! It also has what I consider to be a superior combustion chamber shape to both the 416 and the World heads.

 

And here are the ported intake ports.

 

What are the differences between 601's and 416's? They look pretty similar to me.
Those 1.94 valves look pretty nice, Bull.

 

It is in the shape of the combustion chambers.

You are obviously a scholar and gentleman, and a good judge of female flesh to boot

 

you guys are nuts. but i really do appreciate all the information. thank you all