My brother is wanting to switch out the rear end in his '66 Pontiac Catalina 389. He wants to put a gear in that is in the 3.20-3.80 range. The problem is we don't know what kind of rear it has in it other than it's a peglegger 2.56. I'm going to go look at it tommorow and see if I can figure it out. There are a few eaton posi's on eBay but I don't know if it's a 10 bolt or a 12 bolt. Do ya'll know what will fit? Thanx
