Date codes on exhaust manifolds

[Jim C.]

C2 Fans,

Two quick questions: Are the date codes on 1966 exhaust manifolds judged? How are the dates codes interpreted, Month and Year or Month and Day? Thanks.

Jim C.

[Joe L.]

Re: Date codes on exhaust manifolds

Jim-----

Small block exhaust manifold dates are on the rear surface of the manifold and can't be easily seen. Consequently, I don't think they are judged. They use a usual casting date code of month(alpha character), day, and the last digit of the year.

[Mike E.]

Re: Date codes on exhaust manifolds

Joe is right on, but to add;
Some small block manifolds didn't have casting date. The 901 and 902's never had casting dates until the much-later replacement ones came from GM with dates, with wrong-sized casting numbers, and the casting slag ground off.
965 and 556 manifolds always had the casting dates. Who knows why? I'm not in that elite group, by any means.

[Gary B.]

Date codes on exhaust manifolds; yes hard to see

Jim,

Most of the small block 559 and 042 exhaust manifolds for '66 that I've seen had casting dates, but as others have said they are essentially impossible to read with the manifolds on the car, hence not judged.

Gary