Lookin like my engine has a blown head gasket. I am worried that one or both heads may have some cracks, since the engine has overheated in the past (before I got it).

Can anyone recommend any new replacment heads that are inexpensive and I can purchase new, which will work with the existing L98 TPI manifold? Idealy a headset kit and new heads and just swap them on.

I saw some vortec heads mentioned in this article http://wiki.corvettefaq.com/index.ph...Cam_Comparison
that they said are 420.00. Would those work ok on my engine keeping everything else stock? Any better ideas? And if they are recommendable, where would I find them?

Thanks

 

Sorry, vortec heads will NOT bolt right up to your L98. The intake bolts are in a different location and at a different angle. There are many cheap aluminum heads out now, that is what I would reccomend. Patriot Performance is one I can think of right off hand, they have a budget set of heads for around $1000. Good performance upgrade too. Look around, there are many companies selling budget heads in aluminum or iron that will bolt up to your L98. Sorry I can't provide links or names right now.

 

vortec heads will not bolt up to your existing tpi manifold.

alum heads on an iron block was a sithty idea to begin with...the thermal expansion rates of Al and Fe are very different, requiring movement between the heads/block at every heat cycle (start/stop), with eventual failure almost a certainty...most will not fail until well beyond the warranty period (?????)... head gaskets are most often the victim, but brinneling of the heads is common...resurfacing the heads and installing with proper gaskets may get 'er

 

This is the GM replacement head. They flow at 199 CFM which is OK for a stock L98. I have a set with 1.6 RRs.

http://store.summitracing.com/partde...t=nal-12556463

 

Wow, what a huge difference in price, 600.00 a piece for factory replacement, or 500.00 for a pair of the vortec? If I got the vortec that leaves 700.00 for a new intake if that would be doable. What would you guys do in my situation for the best price/performance? I was hoping to get away from spending over 1k, but if I am already spending 1000.00 for a pair of heads, is there any other heads that cost slightly more but offer improvements in performance worth the money? If I already have the intake off I might go ahead and replace the cam too for a better performing one.

By the way, thanks for giving me a link in your reply, it really helps me to visualize what im getting and what it costs.

 

edelbrock actually has a l98 replacement head that flows much better than stock. my worry is that you may have cracked rings. overheating a couple times can mean cracked piston rings. i'd be nervous. also, there is a good chance that your heads are not cracked. aluminum can take a beating in the heat dept. far more than the old cast iron heads. shaving .05 off the face so you have a flat surface may be all that's needed when you do the change. also, the felpro 1010 gasket is a better piece than the stock HG's in my opinion.

 

A pair of Vortecs is $600 and they don't have the correct cc size. Add more $$$ for milling and money to get an intake that matches. It's not a cheap option. Your 1990 has alum heads and new heads start at about $1000. $1250 seems to be the average. $1,450 gets you into AFR territory -- but you have to mill anytime a head is not around 58cc (assuming no major mods).

My opinion is the best "bang-for-the buck" include TFS, Dart, Edelbrock, and the GM's linked above. Each have strength's and weaknesses. More modern heads tend to mix/burn the fuel better -- which gets better performance and mileage. The Edelbrock's are supposed to have really good reliablity ratings, but a recent post about problems is troubling. TFS have a great design and flow -- but had a bad rep a few years back (plus it was for their 18degree heads). Dart and GM are successfully used and reviewed. AFRs are considered the "best" right now. But, if you want better performance, you also need better intake and exhaust manifolds! Plan on $4K to really change your motor. Otherwise, the consensus is leave it alone.

I suggest taking your heads to a local machine shop. Even cracked heads can be repaired -- especially if you're determined to manage your budget. And, that doesn't guarantee you're free from bottom end damage. At the very least, they can let you know if they're bad.

Have you done a compression test?

 

So I should be more worried about piston rings then heads? Would a compression check be suffecient to check the rings?

 

Jegs has the Vortec heads for under $600.00 a pair. But you have to mod or get a new aftermaket intake.

http://www.jegs.com/i/GM+Performance...58060/10002/-1

The Vortec head is a iron truck head. It will flow much better than the aluminum L98 head. With a stock bottom and cam 199 CFM is probably enough. Here's some good info about SBC heads including the Vortec.

http://www.customclassictrucks.com/t...evy/index.html

Also, I have read that iron heads will not tolerate heat well.

 

What kind of options are available as far as intakes that would work on those heads? I do like the low end torque of my L98 and I read that is one of the good things about the TPI intake.

 

Maybe some nice edelbrocks?

http://www.flatlanderracing.com/edel...heads_sbc.html

They are like $1200 a set for aluminum.

 

I think dollar for dollar Brodix IKs for a bargin priced head is a really good deal for what you get. I think they're going for $800 or so

Also, Consider Patriot, they have some good deals in inexpensive heads. $900 for an assembled head.

 

I bought my bare heads from patriot for about $250 each. There is a reason they are called "as cast". I had to spend about 5 hours grinding them just to make them not horrible. Then I spent $900 on valves, springs, seals, keepers etc and labor for a 3-angle valve job.

Now I have OK heads with really excellent manley and comp cams hardware. They aren't bad heads, but they require lots of work. If you went cheaper on the hardware, they'd be pretty economical.

 

Just out of curiosity, what were you expecting for $250? and advertised "as cast"?

 

For what its worth, I've heard some very bad things about those Patriot cylinder heads from some of the hardcore bracket racers..... poorly cast, thin, etc..... But, I personally have no experience with them and thus have nothing negative to say about them beyond relaying what I have read elsewhere.

If I was you, it sounds like you're on a budget, then purchase somebody elses failed plans...... I was on ebay, I know there is a set of Trick Flow cylinder heads with a starting price of $ 500, I don't think there is a reserve and an option to buy them now for a little over $ 800 I think.... I assume they are still there, do a search at ebay. I know from experience, those cylinder heads will flow in the 240-250 area and easily support a 450 HP motor and are a "big" step up over the stock castings.... with no other changes to your tpi motor, you'll probably pick-up 30-40 hp just by sitting them on top of your engine.

I also recommend www.racingjunk.com as well.... lots of good deals pop-up there as well all the time, just have to keep up with it and be on top of it when something shows-up that interests you.

Good Luck !

 

The Patriot heads are the least expensive and work well from what I have read, but they are cast in China.

Consider Jegs brand which is Canfield and made in the USA. They will cost more but do have better flow numbers.

http://www.jegs.com/p/JEGS/750801/10002/-1/10187
http://www.jegs.com/instructions/555...1411-541_F.pdf

.7 I 260 ex 203
.6 I 259 ex 200
.5 I 258 ex 190
.4 I 247 ex 175
.3 I 201 ex 143
.2 I 145 ex 107

Patriot link:
https://www.patriot-performance.com/...&cat=40&page=1

 

How will those bigger high flowing heads work with his stock cam?
Here's the specs on the cam.

In/Exh Dur@.050" 202'/207' Lift .413"/.428" Lob Sep 114.5'

1.6 RRs will give him another .030 lift. I really don't think that a head that flows over 200 CFM is needed. If he goes too big it might slow the Vette down, right? What about compression ratio? Stock is 58 cc.

How much bigger can you go? Will it affect torque? I say if he's planning a cam, intake and exhaust then he will need bigger heads. But it looks like he just wants to get it running at a good price.

I like the GM ZZ4s because they have been on my Vette for about 5 years with no problems. I'm not sure about the others.

 

IF the cam can only let so much air through no sense in spending money on a head.

On buying those, you wont get anything good cheap. Just my .02

 

WINNER!!! Finally a voice of reason........

 

... Your Heads might be ok. Do some testing on the motor.

...Cast Iron tolerates heat ok. Even Chevy didn't use Aluminum Heads on a regular production SBC Corvette until '86.

...Nearly every Manufacturer has a Vortec version of their Intake Manifold.

...Milling heads to 58CC costs about $200-250 around here.

...I too have heard that the Patroit Heads are poorly cast/machined. I've heard of problems with RHS too.




...ZZ4 Heads are the same as #113 L98 Heads. See #1 above.

...Canfield 197s are pretty good flowing; about the same as the old AFRs. They are about $1200+. New AFRs are about $1450+. 286 CFM.

...Bigger sized Ports can make for less TQ at lower RPMs, bigger Flow #will not hurt. Good flowing Heads will work just fine with a smaller Cam, and show improvements. It's better to have good Heads and a smaller Cam than poor Heads and a big Cam.

...The cam lifts the Valve open(Lift). It opens it from the seat for a period of time(Duration). A better flowing Head will pass more Air/Fuel mixture during this avaliable time.

...you get what you pay for.