C2 exhaust manifold code?

[Eugene B.]

Members,
I am considering replacing the right side exhaust manifold on a '65. The original manifold was cracked and brazed approx. 30 years ago. Mechanically it is fine, just a cosmetic issue.

The casting number is 3750556. It is followed by an X and GM. Not sure what the X means? Also, there is a number under the casting number. It is RH 8 or 6 (it's hard to tell the difference).

Is the RH 8 or 6? a date code that I need to be aware of when purchasing another manifold?

Thanks guys,
Gene

[Gary B.]

Re: C2 exhaust manifold code?

Gene,

The 8 or 6 after the RH is a casting mold number, not a date code. If there is a date code, then it will be on the opposite side of the manifold, and typically consist of a letter code for the month and then 1 or 2 digits for the day of the month. There is no year code. Date codes are essentially impossible to see when the manifold is mounted on the engine and they are not judged.

Gary

[Mark G.]