51Rustbucket, check out Craigslist.org and go under Detroit for tons of parts. If you find a U-pullit, let me know!
Anyway, the 4x4 S10 rear ends are a bolt in and the old Camaro and standard 10 bolts are all over the place cheap. I picked up a disc brake Camaro rear end last fall for $50. If you are leaving it leaf springs in the rear, Mopar parts has spring pads that weld onto your axle tubes for $8 a pair.