Mario at Collin County Truck Parts, McKinney, Texas, has one from his 57 Cameo that has just about zero miles on it but came from behind a 283 Chevy. Don't know if it's the same trans as the GMC but I'm sure that if it's for sale at all he'd sell for half the overhaul price and guarantee it. He didn't care for it's quick hard shifts and replaced with a 700R4. I know the later Buick/Olds/Pontiac/Cadillac had a different bellhousing pattern. Maybe the bellhousings can be switched from one gear box to the other.
