GM rear gears

[PxTx]

Thanks to all who contribute to the exciting forum. I thoroughly enjoy reading the posts and enjoy trying to figure out some of the "mysteries" of Chevrolet.

This evening while laying out the differential internals for my little (16 years old) sister's 69 Baldwin Motion clone/tribute/replica... I discovered a ring and pinion that is somewhat mysterious to me.

It reads 2 GM 3936482 9-37 3 70 11

This has a 37 tooth ring gear and a 9 tooth pinion. My math says it is a 4.33 gear. Has anyone ever heard of GM producing such a gear? I would be very interested to hear you input.


FYI: Although she is building a "clone", the car will never be sold in her lifetime. I say this to re-assure those who are concerned with people building clones that are sold as genuine.