5.7 TPI Vortec heads


Brandon774
10-28-2004, 04:53 AM
I have a 89 Trans Am Gta with the 5.7 TPI motor and wanted to put vortec heads on it. Does any one know where I can get some good ones for cheap and are there any better ones then another. Also if I did that is there any thing else I should do if I where to put vortec heads on or can I just leave the rest of it stock? I aslo want to put better cams in it. What would be the best cam to go with vortech heads. Is there any things I should do when changing the cams to make every thing run smooth and right?

FormulaLT1
10-28-2004, 05:47 PM
www.summitracing.com has a nice selection of heads and there tech line People can be a big help in finding the right set up for your project. Also welcome to the forum.
John

89IROC&RS
10-28-2004, 10:06 PM
The vortec heads are a natural swap for the TPI motors, but the problem with bolting them on is that the vortec heads have a different intake bolt pattern than the older style heads, which makes the baseplate un-useable. Even if you were to modify it with a carbide bit to match up bolt hole wise the ports on the vortec heads are so much bigger that they actually rise up over the lip of the baseplate far enough to stick the end of a pen through. The solution to this is offered by Soggin Dickey Performance Parts. www.SDPC2000.com who have taken it upon themselves to custom design a baseplate to make this possible. designed spesificly for vortec heads and TPI it has larger runners and is worth more hp by its self. Right now i think the price is just under 400 dollars.

Vortec heads are plentiful at the junkyards across the country. Find any 1996-2000 CK platform truck (Silverado, Tahoe, Suburban and GMC equivilents) with the R code 350 engine. Pull the valve cover and check for the head casting number in the rocker valley, you want the heads with the 8? digit code ending in 062. The head castings ending in 908 have pressed in steel exhaust valve seats that limit flow and port modifications. The heads also have a max lift potential of around .480in lift. meaning a mild cam will have to be used, unless you have them machined for more lift. This is a pretty easy machine job that most shops are probly quite adept at by this point. it requires enlarging the spring seats, and cutting down the valve guides for dual springs.

The chambers on the vortecs are a bit larger than those of the stock 350, so a switch to steel shim gaskets would probly be a good idea. but even with slightly lower compression, the heads make more power. The swap to vortecs and the baseplate has been prooven to add 40-50hp to an otherwise stock L98 engine.

as far as cam swaps, it really depends on what the rest of your drivetrain is. you want the cam to match your engine, torque converter, trans, and rear gear ratios. To get a specific cam i would reccomend calling Comp Cams cam help hotline, its toll free, and they are the experts.

FormulaLT1
10-28-2004, 10:08 PM
Who the hell said you where aloud to post in the Firebird Forum 89?

89IROC&RS
10-28-2004, 10:24 PM
i did, someone has to talk about something other than jello ;) i had complaints about a lack of tech advice :evillol:

FormulaLT1
10-28-2004, 10:34 PM
Oh please, read the post over the past couple of weeks, I have answered questions from everything to 455 bolt patterns to LS1 CAI and then we all get to relax in the Jello tub. Your just upset the Camaro Forum doesn't operate so smoothly.

89IROC&RS
10-28-2004, 10:52 PM
haha, still love ya man, even if you are somewhat misguided and confused at times ;)

Genopsyde
10-28-2004, 11:05 PM
Dude, listen to me, Vortec heads blow serious bunghole, get some edelbrocks.

FormulaLT1
10-28-2004, 11:07 PM
And Geno is a expert on bung hole take his advice

89IROC&RS
10-28-2004, 11:09 PM
um, huh???? geno, im a bit confused, upon what do you base this conclution???? granted the edelbrock E-Tec heads flow more, but are majorly overpriced. IF i was gonna spend the dime on the E-Tec heads i would get the aluminum GMPP fastburn heads instead.

Genopsyde
10-28-2004, 11:13 PM
i based it on the fact that I can't use them on my 305 without chopping them all up and hafta pay out the ass for some decent heads. So i'll just pout about my loss and stomp my feet and say they suck anyway. :D

Genopsyde
10-28-2004, 11:15 PM
now that makes me think about your project, what combustion size did the 302 have?

FormulaLT1
10-28-2004, 11:16 PM
I'm sorry 89 But I'm going to have to go with Lord of Poop on this one!

89IROC&RS
10-28-2004, 11:21 PM
lol, he wont have to cut anything up, the sell TBI/vortec intake manifolds for like 200 bucks *shrugs*

oh and the original 302's had small chambers, domed pistons, and 12.5:1 compression. ill have to do some lookin to find out exact numbers. with the vortecs im lookin at around 10.3:1 compression with the 61cc vortecs.

Genopsyde
10-28-2004, 11:25 PM
oh no, I know all about the vortec tbi manifold, i meant milling them down so far to get the combustion chamber smaller and from what i've read, you can't mill them down far enuff to get the 58cc.

89IROC&RS
10-28-2004, 11:31 PM
ohhhhh well you can safly mill the vortec heads up to .04inches, which should take off quite a bit of material and lower the size of the chamber several cc's, the swap to steel shim gaskets would probly do the same too, let me crunch some numbers....

stock combustion chamber size = 58 + 8cc (gasket) = 66cc's

vortec and steel shim gasket = 61 + 2.69461 = 63.6946cc's meaning you would actually raise your compression quite a bit.

and yes i know the vortecs are listed at 64cc's but i have read several times that they are actually closer to 61cc's. however even if they were 64cc's youd be looking at a total volume of only 66.6946cc's, meaning you would only have a chamber roughly .7cc's larger than stock, which would not reduce power by anything noticeable, plus the improoved airflow and combustion in the vortec heads would add substancial power over the factory heads.

FormulaLT1
10-28-2004, 11:56 PM
You got pics of your cars besides the one's in your sig 89?

Brandon774
10-29-2004, 05:43 AM
I don't have any of my poniacs but have a couple of my MR2, Rx7 and 67 Step side. They aren't on this computer. I will have to take some of my Poniac and post them soon for you guys.

FormulaLT1
10-29-2004, 09:06 AM
Cool, post them in the member's ride thread. Thanx

89IROC&RS
10-29-2004, 09:23 PM
yeah ive got a few, mostly of the damage to the RS after the accident.

FormulaLT1
10-29-2004, 09:25 PM
If you have any that aren't all damaged pics, I would appreciate it if you can post some in the member's ride thread.
Thanx

89IROC&RS
10-30-2004, 08:53 PM
dont have them on this computer i dont think, but ill see what i can find, also i havent had alot of luck with the gallery section lately, it hasnt been recognizing me as a member for a while.

FormulaLT1
10-30-2004, 09:01 PM
Thanx in advance for trying.
John

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