C3 1968 Exhaust Manifolds

[Jay L. Flinders]

Does anyone know which are the correct exhaust manifolds for a 1968 427/390 no AC, no power steering, no power brakes? The NCRS judging book I have says Left 3880827 Right 3880828. The chevy parts book and a corvette cross reference book by Technical Ouput Products shows Left 3880833 Right 3880834. Is one with out air holes and one with?

Help. Jay

[Joe L.]

Re: C3 1968 Exhaust Manifolds

Jay-----

That's just how it is. The 3880827 and 3880828 are CASTING numbers. However, they also happen to be the PART numbers for the non-AIR-fitting manifolds. The PART numbers for the manifolds with AIR fittings (which ALL 1968 Corvette big blocks had) were GM #3880833 and 3880834. This is a case where BOTH the NCRS JG and the GM P&A Catalog are correct. That's because the JG is referring to CASTING numbers for the application and the P&A Catalog is referring to the PART numbers. The PART numbers for the 3880833 and 3880834 are nowhere to be found on the manifold UNLESS you're talking about an NOS SERVICE manifold which will have a parts tag or yellow stamp with one of those numbers.

If a 3880827 or 3880828 manifold were to be found on a 1968 or 1969 Corvette without AIR fittings, even though the casting numbers would be correct, the manifold(s) would be incorrect.