BB head casting numbers?

[Jerry G.]

My buddy just purchased a bb 67 . The heads have a casting number of 346236 and a date of C13 79 and a casting mark of GM2T. These heads are on a block 3963512 which I think is a service block assembled in 1969. Anybody have an idea what these heads are and if they are compatible with the block?

[Clem Z.]

Re: BB head casting numbers?

346236 1975-87 oval port open chamber 454

[Jerry G.]

Re: Thankyou Clem

This engine seems to be a strange assemblage of parts.

[Clem Z.]

Re: Thankyou Clem

this may have been done to lower the compression so it would run on the fuel now available.