It's a daily driver, and I must retain all smog and EGR provisions. I can't choose a cam until I get some heads. I'm NOT looking to spend $1000+ on heads. The most I'll ever want out of this car is a dependable daily driver that can keep up with your average LS1 and new Mustangs that aren't excessively modded. 12.9 would be cool, but I'd be happy with a low 13 second car that gets decent mileage and starts right up for me every morning. I would prefer cast iron for a stock appearance unless aluminum can be made to look identical (Can it??). I'm open to the used market. I just need a solid starting point.

I have been leaning towards iron L98 heads.

 

Iron L98 or the 081 305 heads are the only ones you've got to pick from.
Other then that you're looking at aftermarket stuff, and I don't think many of them are centerbolt (why on earth should that be something that controlling your choice of heads??? Valve covers cost $20!)

 

check out this link, alot of good reading info with company links
http://www.aa1car.com/library/2003/eb80336.htm

 

here is a really nice set for 795.00 pair

https://www.patriot-performance.com/...ome.php?cat=40

 

Don't forget aluminum L98 heads from the corvette. They are center bolt.

I think just a nice set of LG4/TPI 305 heads from 87-up is your best bet. They're cheap, correct for your application, and can certainly pull high 12's/low 13's with 1.94 intake valves and some porting on a 350.

 

I just have to keep this thing looking like an L03.

Where can I learn some porting basics? Never done it before.

 

A great "how-to"...

http://www.sa-motorsports.com/do-it-yourself.aspx

Their "kit" is great, but a bit spendy; I find myself using alot of diamond and carbide burrs to do the bulk metal removal, some sanding drums like a 1" and a ½" to shape the ports, and then not so much the little "tootsie rolls", and those only for cleanup type work.

There's a handful of posts you can find on this board, about what people have done and what works and doesn't, what to do & not to do, etc.

 

Here are the vette heads for 500 bucks:

https://www.thirdgen.org/forums/engi...tte-heads.html

 

I think the L98 Corvette aluminum heads would be the best pre-Vortec Center bolt heads . And with some added porting they could be made to flow much like the Vortec's do . But they do have 58cc chambers so the C/R with flat top pistons will be around 10.5.1 with an .041 gasket

 

One more thing on the L98 heads the 1987 and newer one's have no heat passages .

 

Once upon a time I remember reading the 113 heads had some of the worst flowing ports out there. Something like 211cfm at .500" or so. Also something about why the ZZ4 crate motor wasn't putting out all that much. That's pretty opposite to everything I hear on this forum. Anyone remember reading that article, or if there's any truth to it?

 

But like the guy asked the best Center bolt heads non Vortec . You are right about the L98 heads not flowing real well stock . Even 882 heads out flow them when they are both stock . But when they are full ported They flow over 170CCs . And the 58cc chambers help to bump the C/R . Also the angel plugs help fire more HP . COOL I will take a set

 

Hmm, ok, then they are best when ported eh? Ok, fair enough.
They flow over 170cc? What ?

 

L98 iron or aluminum dont have great flow numbers, but mildly cleaned up they will support near 400hp on motor which is enough to make a camaro/firebird go high 12's.

i'd say pick up a set of aluminum L98's as they have screw in studs already, and do some mild porting to them. You'll get roughly 220ish cfm out of them by .500" which is MORE than adequate for your goals.

I was in the high 12's with stock L98 heads, stock L98 cam. So a mild ported set of either L98 heads will do.

I like aluminum for their weight savings and higher compression with the 58cc chamber

 

Aluminum seems appealing for the weight savings however I am concerned about making them look factory. I'm also weary of compression ratio because this thing has to pass the sniffer test. I do tune my own chips. Also, how do octane ratings relate to compression ratio? The cheaper this thing is to operate the better. I have what I believe to be a Caprice 9C1 L05, I can see the spider guide plate for roller lifters. Not sure what type of pistons I have. I don't plan on touching the short block except for cam, it only has about 70,000 on it.

Will aluminum L98 heads accept all my factory L03 emissions equipment and accessories?

What about the exhaust mounting surface and port shape? Will the aluminum heads accept my 1-3/4" SLP shorty headers? If not they are out of the question, I'm not buying headers again!

 

Run by me how compression ratio has anything to do with the sniffer?

 

The high C/R will more then likely help your car to pass . With the thick .041 head gasket and the stock pistons . You should be 9.8.1

 

It will actually HELP pass the sniffer with higher compression ratio. I had to fool CA emissions before, too...

Those L98 aluminum heads will do everything you want. Paint them black with the rest of the engine and you'll be fine. They will run every accessory and everything will look stock.

The key to passing the sniffer is tuning - if you do that you're golden. These heads will pass the visual no problem.

 

i have the Engine Quest center bolt vortec heads on my trans am. i paid $679 for the pair brand new, they have swirl polished stainless valves, comp cams lock and retainers, and heavy duty springs. they are a great out of the box clyliner head and they look very stock. i work for aluminum head rebuilders in portland oregon so i set these next to the patriots, dart iron eagles, RHS, and triton heads. for the price and the ready to go out of the box factor you can't beat them.

 

Alright, well you guys have pretty much sold me on the aluminum L98 heads. What about the D shaped exhaust ports and my SLP 1-3/4 F-body headers?

 

Those aluminum corvette heads don't have EGR crossover. NOX is cause by heat and high cylinder pressure (compression). The EGR is designed to reduce NOX by diluting the fuel mixture resulting in a cooler combustion. Without a functioning EGR and the higher compression ratio you could be running the risk of failing the sniffer test.

 

Painting them black should take care of that

 

They go together like they were made for each other!

 

That pretty much throws out the aluminum L98 heads then. I want to utilize every possible method to get this thing to blow clean, and if that means I lose a couple tenths thats just fine! Its for a daily driver anyway. I'll just look for a set of Iron L98 heads and learn to port them myself. I assume the Iron L98 heads have the same EGR provisions as my current 193 swirl ports?

 

well i dont know the laws in california but if you were to run TPI, you could run vette base and run the vette EGR setup that runs a line off the header tubes to get its exhaust gasses.

else if planning to stay TBI or something like that, then L98 Iron heads is what you want. Port them out tho...clean them up and they will be perfect for a mild 350

 

Since I also live in North Cali, I went with iron heads from World Products Torquer II units. The only reason I went with iron heads besides wanting to look completely stock, is that my engine builder is a friend and he will port these things Penthouse Perfect for cheap. What I seem to find, is that it costs way more $$$ to have a set of iron heads ported- to the point that it would equate to having spent the money on a set of aluminum heads to start with.
There are used heads floating around on the 'For Sale' board all the time. I got mine for just over $350 and they were barely used, had studs and upgraded valve parts already on 'em. Remember: aluminum heads can run a higher compression ratio and should give you room to not have to always run Premium fuel if the C/R isn't way up there.
Are you familiar with 'Chevy High Performance Magazine'??? I bought a couple years of back issues off of Ebay and ran across many great articles on heads. Good Luck, Nitro