First off, I wanted to say thanks to those of you who take time to post advice. I know that I recieve a lot more than I give-out (which is probably best for now).

I need to find a set of headers that will fit my head/car combination. I have a sb w/ GM zz3 350 HO aluminum heads ready to go back into my T/A. The GM part number for the heads is 10185086. I bought these heads way back in 1999. They're very similar to the Corvette L98 heads but with smaller intake ports.

I called Jeggs to order the Hooker Street Force headers for an 83 T/A but they seemed to think that the headers wouldn't bolt-up to the heads.

Is that correct? If so, what options do I have for this application? I kind of thought that the exhaust ports were more or less universal.

 

"D"-shaped exhaust ports?

 

That's not a casting number.... sounds like the part # for the finished assembly, out of the catalog?

Are they 113 castings?

 

Well, he did say "GM part number".

Googling that p/n, looks like 113 castings. Why you say they have smaller ports than Vettes, I don't know - they're the same heads.

 

They definitely have D-shaped exhaust ports and I seem to recall that they were 871 castings but when I google, I don't find that casting number. I have an old article from Hot Rod magazine that says they have 165 cc intake ports which are smaller than the Vette heads......
----------
Is the casting number somwhere on the head?

 

Your headers will physically bolt to the heads, or any other small block chevy heads. The problem will be the ZZ3/ZZ4/L98 Corvette heads are raised .100" from centerline of the exhaust bolts. Most standard 1 5/8" headers, especially Edelbrocks, will have part of the port blocked by the header flange. You can grind away the header flange, or get 1 3/4" headers.

By the way, the L98/ZZ3 heads are the exact 100% the same. The ZZ4 heads have the same springs as the LT4 HOT cam kit, but otherwise, they are the same casting as the L98/ZZ3 heads.


PS: For the nitpickers out there, when I say L98 heads I am talking about the 87-91 Corvette heads. I know the '86 Corvette aluminum heads are slightly different.

 

That's one I've never heard.

'86-1/2, to be exact. . .