I was talking to a guy I know that I was going to pull my heads this winter and do some work on them. He lets it slip he has a set of sbc Vortec heads lying around that he picked up off a wrecked truck. So I asked how much and he says he figures they need rebuilding so $200 give or take.

Does anyone know if that is a deal or what ? As far as I know you have to use a Scoggins-Dickey manifold to adapt the TPI what about EGR ? These manifolds cost about $500 CDN last I checked, maybe more ?

The engine shop says the Vortecs flow 220cfm out of the box and when they rebuild them they can get up to 240cfm with a few hours port work. That is alot of flow. My stock 305 heads flow about 165cfm.

Comments ? Anyone done a vortec swap ?

thx,
RP.

 

I want to do the same thing, except I'm having trouble finding used heads. If you don't want them I'll buy them off of the guy.

 

Great idea and $200 is a decent price. Even to buy brand new the bare castings of the Vortec heads without the valvetrain is not too bad...a set for GM is around $350. As far as the SDPC manifold, I think by the time you get it up here you're probably looking at about $600, so not far off. If the heads need rebuilt, then I would highly suggest going with the setup that they tested in Chevy High Performance...Vortec heads and SDPC manifold, LT4 1.6 roller rockers, LT4 springs, HOT cam and HO valve kit (something like that). But even the Vortec heads and manifold alone are a good mod.

 

Get them. Have the decks cut as much as the casting will allow. Don't let the guy gog them out or touch the chambers. That's a great way to wreck a set of vortecs. Have the ports cleaned up (casting flash removed, polished) and have the valves back cut. Vortecs are the shiznit. The HotCam would work great except for a 305 won't tolerate that kind of valve lift. My suggestion is the LPE "216" cam or you could use the HotCam with 1.5 rockers. GMHTP did a little write up on a Vortec/Hotcam 5.7L TPI engine earlier this year. It made great power.

 

.......oh and Scoggin Dickey sells a kit that adapts your EGR to the new heads.

 

Maybe have the chambers cc'd - I think they can be between 62 and 64 but you need 58 for a 305.

 

58cc would be high AFAIC. I'd spec the head/head gasket thickness out so that a compression ratio of around 10:1 was acheived.

 

Fair enough - I was mainly raising that as an issue that would have to be resolved one way or another - although I thought 305s were supposed to be 58.

 

Sorry, didn't mean to step on your toes. Your right, the heads would need to be decked to acheive decent compression.

 

I didn't regard my toes as having been stomped - like I said it's just an issue to consider - if someone else has a better answer then that's the one to go with. I used to use beer to cc my 2 stroke motors with until someone told me that's not how you do it.

 

Beer? George, that's a waste.

 

Palric.. if you don't get them I am... in other words its a good deal for sure, even factoring the price of a new manifold since you got to get one that works with the heads...

 

If the heads are to be decked so does the intake..Too much $$ IMO..I would just get an AL L98 head,port or bowl work,ZZ3 cam and done with..Save 40lbs on the front end in the process..IMO its still better to just get a 350 long block than to rebuild the 305..BUt if your set on not touching the shortblock I wouldnt go for the said heads..Your rocker arms might not work either..Vortec outflows AL l98 heads stock but for a 305 theyre both enough ..IMO..

Daz

 

Actually the beer went through the kidneys first and then into the motor.

 

Ive always wondered about the vette heads. how much do they cost new or is it better to buy used and have em redone? I know they are built for torque but can they be easily re worked for some higher end hp?

 

Ive seen em on 11 sec NA cars and many many 12 sec cars..I rather get em used..as long as theyre

Daz

 

I was going to stay with the stock shortblock and cam. Throw on a set of headers and hi-flow exhaust pieces.

I figured I'd setup the vortecs to work with the 305 and use 1.7 RRs supposedly these will work with vortecs (rather than 1.6s). I am going to call Scoggin-Dickey today to find out what the real cost is for the intake.

I have no idea what the cc is on the Vortecs I figured they'd be on the 70+ range because they came off a 350 but there were some tech articles I read way back that said the are all mid 60s ??? Not sure where to get the facts on this ? If mid 60s I can get the heads shaved and use appropriate gasket I agree AcceldZ somewhere around 10.1 would be ideal.

Daz -- if I shave the heads do I have to also do the manifold ? There is a 1/4 inch gap already where my stocker meets the block front and rear (lotsa gasket goop used there) I figured I'd just use less goop. Oh yeah the distributor shaft might sit differently too -- this is why I hate these kind of mods...

Question is bang for buck for all the work to be done ? I figure this mod (manifold, heads, AFPR and headers) will put me around 300hp assuming I am currently at or near 240hp (dyno day is coming).

For comparison sake the vortec upgrade will cost about $1200 by the time I am done. It will cost me about $600 to have my factory 305 heads hogged out with bigger valves installed. A set of S/R Torquers designed for the 305 that flow about 170cfm cost about $1200. I have no idea what used Vette AL heads cost nor what it would take to make them work on a 305 ?

thx for your replies,
RP.

 

If your'e gonna shave the heads that will make a difference in cc volume then yes you have ot shave the intake too or else the ports wouldnt line up(as good anyways)..And with the 10:1 compression youll be pushing the limit on detonation(read:less room for error)Minimum of 94 Octane and you need a big cam..THe LT4 HOT caam spec could be the smallest size..If you go smaller cylinder pressure will be higher then detonation..Youre lucky if you can do the heads for $1200..SInce you cant use the springs it came with(doesnt support lift over .500 I think)you need new ones,I wouldnt keep the pressed in studs either(thats just me)...Springs has to match the cam..consider buying that too..

Vortec outflows the vette heads..but for the power level you want I would go for the ZZ3 heads..vette AL heads bolts right you current setup..The only thing you have to change are the spark plugs.FYI these same heads made 345HP on the ZZ3 motor,springs are good past .510 lift,58 cc combustion chambers.40lbs lighter and can be repaired if damaged..These heads have thick casting,great for port work etc..


Daz

 

Thx Daz,

So if I find a set of ZZ3 AL heads I can keep my stock cam and manifold ? What about EGR ? Does the ZZ3 accomodate EGR ? Any idea what the cc is ? How about cost what are these kind of heads worth ?

I plan on sticking with the stock cam when I eventually swap out for a 350 or some such I'll get a decent cam but until them I plan on heads, headers, AFPR and chip (plus manifold if vortec heads).

thx in advance,
RP.

 

I thought you were getting a super charger....

Vortec heads are a BIG job to retro-fit... unless you buy the SDPC base.

 

You would be able to retain the stock cam and manifold. The L98 heads do not support EGR. The nominal cc for the chamber is 58cc's. You should be able to pick up a set of used L98 heads for around $350-400US. Look for '88 and up 'Vette heads and the ZZ series crate engine heads. They are the same except for some valve spring and retainer changes.

 

thx AcceldZ -- so if I go with the vette AL heads EGR is not supported ? DO any of these heads retain EGR -- I want to stay emissions legal. This was why I was originally looking at the S/R Torquers they have EGR passages but they cost $1200 and I am not sure how useful they'd be when I eventually upgrade to a 350 or 400.

thx,
RP.

 

correct me if Im wrong I thought those Vortec heads dont have EGR passages also..The Vortec motors run on divorced EGR's..
Your cam would good on it..even better with 1.6 ratio rockers

Daz

 

I thought the vortecs had no egr passage but Scoggin-Dickey has some kind of egr kit you can buy with your TPI manifold and vortec L31 heads. Makes the setup emissions legal.

... too many mods drifting too far from factory means lotsa headaches.

Maybe I oughta forget it and pour some money into t he old 305 heads -- 2.00 intake, 1.6 exhaust, 3 angle grind plus porting and polishing, throw in some 1.6 RRs as well and a decent set of headers ought to make for a 275hp 305.

RP.

 

Or maybe you'll just forget about it, and leave it stock like you always do Just kidding man... I think it's time to mod that low milage unit.

 

What would you say about comparing vortecs to the AL vette heads all you knowledged people in the area (daz, acceld, anyone else I missed)? Flow, hp support, etc? I thought the L98 heads had the small intake valves for more torque but less high rev hp? Would it be hard to slap some big ones in there?
greg

 

Here is what I know(pls. correct me if needed)
Vortec
Pros
1)Better flow numbers/design....can support high horsepower
2)Cheaper
3)Iron heads retains heat which means hotter combustion chamber temps which means more power
4)Dunno large valves would fit
Cons.
1)Thin castings..
2)You need to get the matching intake base
3)The spring it comes with limits the cam choice and the heads potential(solutrion :new springs)
4)Iron heads are more susceptible to detonation since its hotter..(flame burns prematurely which causes the 2 flame fronts to collide
Vette heads
Pros
1)Can support high horsepower(400HP) if ported
2)Aluminum dissipate heat better which means you can run higher compression ratio = more power with the same gas
3)AL heads are lighter
4)AL heads can be repaired if damaged(exampe is if a valve hit the chamber..lol)
5)New Vette/ZZ3/AL L98 heads came with springs that can handle over .500 of lift(345 HP ZZ3 crate motor has /510 lift)
6)Thick castings..The runners doesnt have to be enlarged to make the flow "better"(Flow is not all about peak numbers)
7)Bolts up to a thirdgen
Cons
1)more expensive than Iron heads(Vortec)
2)Warps easier than Iron heads
3)Can only fit up to 2.0x" intake valve and 1.6" exhaust valve without major(read:expensive)modification
4)Angle plugs might make plug changes harder(in my case it was the opposite..its easier)

Daz

 

Thanks a ton daz that was ADSACTLY what I was wondering and I am sure it is useful to others as well.
the AL L98 vette heads are angled plugs? That means they would never fit my SLPs?

 

My heads are angle plugs and my SLP headers are 1 3/4"..There are no Accel shorty plugs that fit my application..All plugs gets taken off from top..3 of the 8 plugs I have to use a plug socket that I shortened 1/4"..SLP sells a similar spark plug socket..expensive though


Daz

 

Sweet thats good news. how do you like those headers BTW? Mine should be here early next week. Anything I should buy that doesnt come with the install kit (which I assume is a rip off but I ordered for simplicity and quickness)? B i t c h to install?

 

As far as I know they are 58cc from '82-'92. I found out about this back in '93 when I built a 350 with 305 heads. Had to get 10cc dished pistons.

adious,
RP.

 

HEY MAN I'm NOT stock -- I use after-market car wax. We'll find out how much HP it makes on dyno day... hahahahaha ...

Hey buddy it has to be the RIGHT mods. I don't want to build a freak that is held together by gasket goop. Stuff on the go:

- I'm picking up the suspension goodies from ROCHEAD should help my launch times.
- I'm building a custom air intake off my hood bulge now this will be cool.
- spec'ing out head work for the winter buildup this is tough figuring what is the best/easiest bang for the buck. Once I decide I won't waste anytime doing it.
- looking in the wreckers for a rear-end from an '84 Z28 5-speed HO they came with a 3.73 posi disk brake. Definitely want to run a 3.73 rear the 3.42 isn't high (low?) enough gearing for my needs.

Lotsa stuff on the go always waiting for the right deal at the right price. Found a 350 4-bolt block for $50 with steel crank what a deal but it is not a roller block to I take it or pass ??? Decisions decisions eh ?

adious,
RP.

 

You should buy that block & crank even if you don't use it. You will have no trouble unloading those pieces... they are as good as cash.

 

I've got flow numbers from the Aluminum L98 heads up on my homepage, along with pictures. Just thought ya'll might wanna check 'em out.

 

I was seriously looking into an ATI Pro until I found out the $1995 USD was just for the charger unit the other stuff mandatory to make it all work -- added up to another $1000 USD.

Well that isn't such a deal after all. So I am checking other more common options, heads, 350, etc.

RP.

 

I look at it this way..Youre gonna rebuild the 305 sometime..why not start with a 350?Wait for the 305 to be sick then replace with the 305...It will cost you more time and money doing it one part at a time..I know doing everything at once might not be financially possible..But try to do a lot of things at once..I would start with a 350 block..then work from there...I only get(and install) bolt on parts if it replaces a broken part..IMO..

If I have to do it over I wouldve gone solid roller cam,coated ultra light forged pistons etc..
Daz