I have a gm aul intake, casting number 10185024, with what is said to be a winter foundry snowflake cast in to it. I know that this is a z-28 style intake that was sold as a service piece. my question is how to date the manifold ? Their is no "date code" that i recognize stamped or cast on it. The only marking besides the casting number is on the front bottom . It reads /312832. I have no clue! As always , any information that you cane provide is greatly appreciated!!!
Thank You Jim H.