BB exhaust manifold

[Calvin C.]

I have a 73 454 I need to replace the headers with stock or stock looking exhaust manafolds. I have noticed that the supliers show BIG BLOCK Manafolds from 68-70 or 68-72 but not for 73. What are the diferences and where can I get a corect looking manifold.
TAHNKS AGAIN
Cal

[Joe L.]

Re: BB exhaust manifold

Cal----

Big block Corvette manifold castings were the same for all 1970 to 1974 Corvettes. In fact, the right side manifold casting was the same for all 1966 to 1974 Corvettes with big block. This casting is GM #3880828. The left side manifold castings changed for 1970----1966-69 used GM #3880827 and the 1970-74 casting was GM #3969869.

While the castings were as described above, there were 2 sets of finished manifold PART numbers. That's because these manifold castings were used for BOTH AIR-equipped engines and non-AIR-equipped engines. Since all 1973 Corvettes used AIR, you will require the 3880828 and 3969869 castings which are drilled and tapped for the AIR fittings at each exhaust runner. These manifolds ARE available in reproduction and you should have no trouble finding them.