Casting Number Question

[Brian W.]

After checking some rear axle castings that I have I came across one cast 3788812 with a "P" cast on the side part-way towards the front (the "P" is 1.5" long). Can anyone tell me if this was used in Corvette production? I can't read the date. Thanks.
Brian

[John H.]

Re: Casting Number Question

Brian -

3789812 (not 3788812 - check the 4th digit) was used for '61-'62 Corvette Posi center sections, but only if it has a "thin" "P" cast in, which indicates that it came from Detroit Gear & Axle; the same casting number center section was also produced at Buffalo with a "thick" "P" cast in, but those were only used on '58-'64 passenger cars. The "thin" "P" has about the same raised cross-section as the "GM" cast adjacent to it; the "thick" "P" cross-section is at least twice as wide as the "GM". The Corvette part has a single-digit year code stamped on it, and the passenger part has a 2-digit year code.