A wrecking yard in Spanaway that is about 30 miles each direction from my house definitely has a g body rear end, I saw a few cutlasses while I was scrounging parts. I try to go to that yard every couple weeks and support them, they are really good about pricing and having lots of older cars. It is called "Dicks u pull it". Unfortunately they do not have any Buick Regals. I could be persuaded to drive my truck out there and find a decent rear end, but I'd have to make some money for my time, labor and gas.