soarestransam

Hey everyone I'm picking up a set of 202 chevy heads off 70's or 60's corvette that had a 350 in it I'm looking to get a new top end for it cam, lifters, rockers, etc the heads do have to be rebuilt first so once I get my 194's off that's when I'll do the top end swap but what's a good set up to go with bottom end is bored 30 over with forged wesco piston with a 9.8:1 compression stroke is stock 3.48 inch bore size is 4.030

1gary

I am confused.You spent what 500 to 800 dollars for Wesco pistons and now in their best day will never flow anything close to aftermarket heads let alone you needing to start the work on those 202's with harden seats for today's gas for starters.I don't see the logic here.

InfernalVortex

iTrader: (4)

First off, everything used you buy is going to "come off a corvette" - dont believe it for a minute. Most of those old "classic" muscle cars were pretty slow anyway. Those inflated horsepower numbers they "officially" had were SAE net horsepower which were under the most ideal of ideal situations, measured at the flywheel with no accessories, free-flowing special intake, and headers. Also a lot of them ran higher compression ratios and ran on leaded gasoline which helped them make more power - they ran into problems after leaded gasoline was phased out.

Don't get hung up on ANYTHING that came out of ANYTHING prior to 85ish. Even old school "camelhumps" have been far surpassed by modern factory Gen I heads.

There is no such thing as a "202" head. That's usually just a way that unscrupulous or just poorly informed people sell junk, crappy smogger crack-prone heads for top dollar because they have larger intake valves (2.02 inch) put into them. The intake valve size is, in the grand scheme of things, relatively unimportant in regards to performance.

Here is how it works:
Phase 1 - you get junk smogger 70s 350/400 heads for free because people cant even give them away.
Phase 2 - you install 2.02 inch intake valves in them.
Phase 3 - You sell for more than the cost of new valves

In some cases they install them and realize that going to a larger valve actually hurts power where they need it and in general realize how poorly they perform, and they sell them after that.

You need a cylinder head CASTING NUMBER, not backwoods marketing jargon. Modern heads are far superior. Some Iroc L98 heads (083) or C4 corvette L98 (113) heads would be a far better choice for a good 350.



If you're on a budget you're limited to factory heads, if you're cheap go 083 heads. If you got the cash, get 113 heads or vortec heads (906/062/060).

Edit: I see you have an 89 GTA. If you had a 350 TPI engine from the factory and reused those heads on your 355 you'll most likely LOSE performance by switching to "202" heads.

five7kid

iTrader: (14)

soarestransam

ok so what ur saying is that 202 heads are just a pile of junk an im better of finding a set of iroc z heads or a gta heads with a 350 tpi in it if im going cheap but if i have the money im better off finding a set of c4 corvette heads i believe these are the aluminum heads i know that those style heads are the ones that have the center bolt valve covers an the intake bolt pattern is different then pre 86 an down style intake manifolds like i have on my 355 now. i will be take ur word of advice on this one an find the aluminum c4 heads do u know of a companys that will sell a aftermarket intake for it for a carb setup

Apeiron

Any SBC carb intake will fit aluminum L98 heads.

soarestransam

i did not know this i thought the 2 center bolt holes dont line up or do i have to just grind the hole bigger inorder for the intake to bolt on also can u tell me what year the 113 1.94 aluminum heads started i found a set off a 87 corvette with a l98 in it but when i look it up on a chevy head casting site it says they started in 88

Apeiron

Just get an intake that matches the center bolt angle.

113s are 1988 and up with vertical center bolts.

A 1987 Corvette has 128 heads with angled center bolts.

soarestransam

Are the 128 heads the same as the 113 head in intake valve size an are they aluminum also do they have the 58cc camber

88 350 tpi formula

iTrader: (9)

I know its been awhile since ive checked out the aluminum l98 head prices but id be willing to bet a set of vortec heads are still cheaper and flow very well. just need the matching intake for tpi or carb is all..

soarestransam

Where do I find these set of heads are they on camaros an firebirds or would I have to go find a set in the bone yard an rebuild them

Jim85IROC

iTrader: (2)

128 heads aren't the same as the 113s. They are basically aluminum 083s. They do have the small 58cc chambers.

88 350 tpi formula

iTrader: (9)

someone mentioned them before "If you're on a budget you're limited to factory heads, if you're cheap go 083 heads. If you got the cash, get 113 heads or vortec heads (906/062/060)."

im not sure if these are the right casting numbers or not.. i would check mortec casting numbers they came on trucks with 350's 97 98 style get the casting numbers though. you can tell by the bolt pattern but there are hundreds of jerks selling center-bolt swirl-port heads as vortecs so educate yourself..

these need the valve guides cut down a little when going over .475 lift but are one of the best bang for the buck heads

always use springs that will match the cam..

here are some in jegs.. http://www.jegs.com/p/GM-Performance...49896/10002/-1

Jim85IROC

iTrader: (2)

For not much more you can get brand new Vortecs from Skoggin Dickey that are already cut down and set up with springs good for .550 lift.

InfernalVortex

iTrader: (4)

906 and 062 are by far the most common Vortec 64cc castings. You can always tell Vortecs because therea re only 8 bolts holding on the intake.

http://www.chevymania.com/tech/vortec.htm

I have 906 heads. 062 heads are the same thing. xxx060 is the GM part number for either of those casting numbers without special valve seats or other special installations. The hardened valve seats can be found on some 906 or 062 heads and hurt flow, so avoid them if possible, but if you end up with a head with them a good valve job will take care of it just fine. A magazine a while back got a hold of 906 heads and those particular ones happened to have the hardened exhaust seat for heavy duty trucks so they said to avoid those castings, but there are 062 heads with hardened exhaust valve seats too. Anyway if you want to read up on that read this link:

http://www.nastyz28.com/forum/showthread.php?t=56505

I think some of the ones sold have an 060 casting number like the part number, but Im not sure. These would be ones you buy directly from GM I think if they exist.

Thirdgen89GTA

iTrader: (5)

Vortecs are basically the iron SBC version of the iron LT1 heads found on the B-body LT1. Good heads for the $$$ spent. They aren't no AFR heads but they are much better than factory L98 heads off a thirdgen. only issue is you need a vortec base for your TPI, or a vortec pattern intake.

soarestransam

Ok so I guess the 194's I have now are junk as well even with the whole 64cc chamber wow I'm so angry at my engine builder payed big bucks for crap on my 355 getting really angry with this whole build I'm just at the point of finding a lt1 or ls1 an doing that swap with the t56 yea my trans am will have to sit for quite a few years but it will eventually get done I guess :-(

Thirdgen89GTA

iTrader: (5)

Before I knew what heads casting #'s and cam profiles were and before I came to this site I once bought a Re-man for my then "new" car, my GTA.

The reman was supposed to be a direct replacement L98. What it really was was a 350 TBI motor with the wrong cam and the wrong heads. The place who built the engine basically said it was a direct replacement because it bolted in. And i was SOL. That engine thanks to the cam and heads differences never passed emissions.

Now i know better. At the time though my dad was helping me to get a new engine, and he didn't want a used engine. I would have been better off with a used L98, at least the cam and heads would have been right for the chip in the car.

1gary

I am still confused on the point that this O/P bought relative expensive forged pistons,but seems want to try to get by with whatever heads.Back in the day we where thrilled with the thought of oem 202 heads that produced 375 to 400 hp.And those where ported to as much as the oem castings would allow by Mondello.Aside from the fact 202's that where not cracked made them scarce,and the fact the casting did allow for any serious flow numbers,is the main reason why aftermarket companies came in being.

The truth is when I started planing for my 383 build,I was considering Vortec heads from GMdirect.But as I started to machine the block and consider SCR's with head CC's,I changed up to RHS heads.And yes I know tons of you guys are AFR fans,but I do think you get a better deal with RHS.

Cast VS Aluminum.If your trying to drop SCR by using a aluminum for todays gas,ok then use them.It is a band-aid fix to a wrong piston selection/poor planing for decking the block.And it is expensive.If your thought is a wt savings on a street driven vehicle,that is just total B.S.because it just doesn't impact it that much if at all.I have been a swap meet vendor for about 20yrs buying at auctions SBC parts.We do have a keen eye while buying the same.For that whole time we have never seen used aluminum sets of heads that did not need work.Bottom line is the aftermarket cast iron sets for the long term are more durable.

Intake runner sizes.I think I have posted this before,but the formula for a rule of thumb is C.I. x .5 = about the size of a intake runner size.Using that as a baseline,you can move torque curves and peak hp's around changing the intake runners/cams.There are any number of on line dyno's that you can plug in the values to see the differences.

I am posting this for a record.This O/P bought a piston that on cold starts is going to do the forged raddled.The Icon piston design has addressed this with a offset piston pin and cost alot less.My two cents worth is there are race car parts and street parts,so you sheet build the total package for the end intended use.Some of the race rings needed on race pistons are not designed for today's gas or any street use.They are smaller in size and have less tension.So a "like Mike" for the street just does not work.I am saying that with tons of 9.90 car builds.

InfernalVortex

iTrader: (4)

You're talking about whatever head you had back then that had 2.02 inch valves put in them. There's no standard "202" head. These days they just put 2.02 inch valves into craptastic smogger heads and scam people with it. There is no casting number for "202" heads, they can be anything with nearly any intake port and exhaust port, usually crappy ones since heads that are worth anything are sold as what they actually are, ie " ported 083s with 2.02/1.60 valves", not "202" heads.

A couple of advantages of aluminum are weight and better port shapes due to advantages of working with aluminum. I want aluminum heads for better weight distribution and weight cutting mostly. There are a LOT of factory OEM aluminum head applications these days too.

Thirdgen89GTA

iTrader: (5)

There is a very good reason most engine MFGs are going with either aluminum head/iron block, or completely aluminum engines. Its weight savings.

A SBC iron head assembled is darn close to 50lbs on its own. A aluminum LT1 head which is pretty much the same thing is barely 25lbs assembled. I bought a set to have ported and the combined assembled weight with packing material in the box was 48lbs. Thats just 24lbs a head.

Saving nearly 50lbs off the TOP of a motor has some very nice benefits for those who are concerned with weight loss. It is also cheaper for people to work with aluminum and to pay other people to port it.

I think I remember Aluminum as being roughly 1/3 the weight of Iron for the same size.

1gary

About 20yrs in 9.90 cars.Formula for wt is 100lbs savings is about equal to 10 hp.Bare bones truth.Read less the ad's in the comic books and please do more deductive logic.The idea that wt savings on a street rod is pure

The clean cast that is offer by RHS is more a advantage.

OEM's are building problematic Aluminum heads that is a consent repair listed in a trade mag on line Engine builders .com.Don't kid your self.OEM's to cut costs will and do anything.

What I am posting isn't a guess.It's your choice to learn from that yrs of experience or not.

1gary

Surely there are cast iron aftermarket heads that equal or go beyond aluminum heads.The nature of the material heating and cooling at a different rate than the block it's bolted to is a issue.I wasn't kidding what we have found in the used aftermarket heads and what they need to be repaired to make them useable again.The swap meet days we sold at must have been over the yrs 500 sets sold.No kidding.

Thirdgen89GTA

iTrader: (5)

Lets dissect your post for a bit. Cause I don't understand any of it.

No, in 1990 the formula for 100lbs weight savings all depends on the total weight of the car, and the total hp produced. You should compare POWER to Weight for both cars. Its a ratio, not static at all.

Lets use an example. A 1992 Camaro Z28 with an L98. Say it weighs in at 3350lbs and has 245hp. This Camaro is moving 13.67lbs per 1HP the engine made.

So lets take the statement 100lbs is worth 10HP. How true is it? A little math and we can proove or disprove it.

So the ratio is 13.67lbs to 1HP for the Z28. If the Z28 made 10hp less, how much weight would have to be lost to equal the same performance? Well that's easy. Take your ratio of 13.67lbs per HP and multiply it by 235hp, 10hp less. To achieve roughly the same acceleration with only 235hp the Z28 would have to weigh in at ~3213lbs.

3350lbs - 3213lbs = a difference of 137lbs.

But what if we are talking a high HP car like the new Corvette ZR1. The ZR1 makes about 640hp and weighs in near 3350lbs. So that ratio comes to just 5.23lbs per HP. So if the vette made 10hp less how much lighter would it have to be to acheive the same acceleration? Easy 5.23 * 630 = 3297lbs. Thats only 53lbs.

So on on hand we have the phrase 100lbs is worth 10hp. But I just posted 2 examples that show 100lbs is not worth 10hp in all cases. On one hand 10hp is worth 137lbs, on the other its worth only 53hp.

___________________


What does this 50lbs at the the TOP and front of the car save you? Better weight distribution, braking, acceleration and handling. All to marginally small degrees but if you could test it and make the weight loss the ONLY variable you'd see small benefits everywhere.

Now take that concept and apply it to the whole car. Aluminum heads, aluminum motor. Fiberglass here, Carbon fibre there, magnesium wheels....Pretty soon those weight savings add up to a substantial amount.

Aluminum is not a cost saving measure. Its actually more expensive. Why are MFG's doing it? Because they have CAFE standards to meet and every lbs lost means the engine has to do just that much less work to get the car moving. Increasing efficiency and performance at the same time.

More so Performance cars do it because every pound less means more work gets done with the same power. Less weight means faster acceleration. Less weight means increased Geforce loads before tire slippage occurs. Less weight means the brakes have bleed off just that much less kinetic energy into heat and cars stop in shorter distances.

1gary

So it's all good because 100lbs doesn't equal 10 hp.Right??.So than following that logic,50 lbs doesn't matter all that much either.

Just think of 50 lbs effect the steering,traction,and over all performance.Errr-nope.It doesn't.That's silly.

Thirdgen89GTA

iTrader: (5)

Its not about each individual weight savings but everything together. If you can save 50lbs and make the same power for nearly the same $$$ why NOT save the weight?

I think you underestimate the advantages of dropping 50lbs off the front of the car when it comes to handling. It has a larger effect on lateral weight transfer than it does on acceleration or braking.

1gary

It's a well sold miff. A "like Mike" street car trying to be a super gas car.

Core issue.................once again the aluminum heads long term are not as durable.Take that to the bank.$$$$$$$.And please consider we not talking about grandma driving her OEM to the grocery store.

1gary

Oh-if your that aware of the wt of a street driven car,be very sure you kick put your passenger before any stop light racing.

Thirdgen89GTA

iTrader: (5)

You've done such a wonderful job of proving your point about aluminum vs iron durability. Please continue to do so. So ignoring all the crap gary brought up here's what other people have posted.

Old smog heads with 2.02 valves are only valuable if you want a boat anchor and can't find one. New heads, iron or aluminum are lightyears beyond them.

Personally, if you can afford the slight extra expense go aluminum. There isn't any reason not to. Look at the modern industry, just about EVER car out there comes with aluminum heads. Must be a reason for that.

soarestransam

everybody needs to get along im gonna find these aluminum heads if it takes me forever trans am is coming off the road on nov 1st so i can even start saving up for a afr heads i seen them in a summit book as long as they are aluminum an have the 55cc chambers ill be good been even thinking about dropping the tpi setup back in my gta i got a whole eldelbrock tpi intake manifold. runners, an plenum sitting down in the cellar that i can get ported as well looks like the carb days are over for me :-)

1gary

Don't look at my post count.Read what I said.About 500 used sets sold over the yrs and not one..........................not one that didn't need guide repairs or be through back flat or a rocker stud welded or something.Not one!!.Your confusing apple to oranges.Here we are talking about buzzing up engines.

Old dogs that stay up to date like me,hardest thing to do is to try to explain the facts of real street experiences.

InfernalVortex

iTrader: (4)

Aluminum heads probably arent as durable due to the nature of aluminum, but they've been in factory Corvettes since the 80s, F-bodies since the 90s, trucks since 2000 or so. They cannot possibly be THAT bad given their abundance in OEM applications. OEMs will cheap out where they can but aluminum costs MORE than iron and more than that the OEM's have to WARRANTY their parts. If their heads start failing all over the place they're not gonna make any money.

And Im sorry I havent heard any rashes of cylinder head failures in any OEM GM application with aluminum heads. Old smogger heads I hear lots of bad things about due to quality control and thin-casting issues leading crack-prone heads, and those are generally what end up as your "202" heads...

If I ever got a used cast iron head I'd still have everything worked over. I wouldnt expect 150k mile cast iron heads to be "ready to bolt on" either.

soarestransam

ok so i tryed also finding them on autozone website but when i look up a 88-89 corvette it doesnt come up with the casting number last 3 113 its really strange is there a part number i can get to actually look them up cause if so ill get a set off of there

1gary

Our race operation in 9.90 drag cars has for yrs been in the top 4.Don't get that kind of results not being in the loop of current day tech.

My comparison is cast new to aluminum new aftermarket heads.I got a friend that is a huge mid west distributor that got stung with loads of defective heads and took the lost.There is a business behind the scenes in parts that most end users is not aware of.To get a feeling somewhat of what is going on there,I heavily suggest to bookmark www.enginebuildermag.com

It effects what to buy and why.The main thing to consider,well really one thing,is much of the aftermarket parts are off shore sourced and alot of it is machined off shore where the Q.C. is a serious question.

We bought and sold every brand of aluminum head you could think of and one common thread is what I posted.

1gary

After explaining my background and having face on face meets with them,I am saying the cast iron RHS heads are packed with dollar for dollar the biggest bang for your buck that will keep pace with most aluminum aftermarket heads and will out last all of them.

InfernalVortex

iTrader: (4)

I rethought what I posted and edited it. I got kind of hot headed for a second. I apologize.

Also, I completely agree with what you're saying about it being machined off shore. Blueprint Engines made a big deal about the fact that they machine their new aluminum head offering in the states - but it IS cast offshore but at least they were upfront about it. I dont think I'd have a problem buying their heads, but at the end of the day i've got Vortecs and they may not be the best heads on the planet but Im not sure the upgrade is worth the cost and time involved for the horsepower gain I would get. My camshaft is the limiting factor in my build anyway.

I dont think heads like the cheap pro comps and whatnot are a waste of money and bad, but i think you kind of play the lottery with cheap aluminum heads. AFR's and GM heads I dont worry about so much. And there are other brands I happen to know to be fairly nice stuff that I dont worry about. But the new craze for cheap aluminum heads machined by the lowest bidder will definitely cause problems like you're saying.

But I dont think quality aluminum heads are problem prone just because they're aluminum. The things you mention are issues and engineerign challenges, but they've been successfully tackled for 30 years.

Jim85IROC

iTrader: (2)

there is no shortage of high mile C4 corvettes out there with no problems. My 91 had 91k on it when I sold it and I never had a problem. Likewise, almost every modern car has aluminum heads now, and their durability and longevity is just fine. Perhaps poorly designed aftermarket castings are problematic, but don't blame that on tue material.

1gary

I lost my last post.Well things happen like that I guess.

Rest assure that the 9.90 engines are aluminum headed.But we are doing laps and pretty much at idle the rest of the time.I am saying that isn't a fair to compare that to a street car either because we are buzzing those alot while racing.Also,the 50 lbs for that application even through a small pc of the wt reduction means alot.

I do know how long oem heads have been on the market.To compare that to what we intend to do with engines isn't the same thing.I am reporting what is found in the market we use those heads.If you do agree that aluminum is a softer material,then it isn't a stretch to agree the aluminum has a harder time holding valve guides in place over time,rocker studs in place over time,holding deck surfaces flat,etc.

If you go to the RHS site to review what is offered in cast iron,I think my point will become more clear.I don't buy into the idea of 50 lbs meaning that much on a street driven vehicle.

Just check out the site and I do think you will see a bigger bang for your buck over the long run.