I have a 55 2nd and recently put a 10 bolt from a 70 el camino on mine. It is a nice fit. A bit tight between the bed sides and the tires, may have to put on a panhard bar to keep things from moving side to side. I have 17 x 8 rims on.
The one I bought was rebuilt and had a new posi put on. I had to do a lot of "cleaning up' to do (remove a lot of perches, etc,) but fits nice. (Drum brakes still, 3.73 gears)
I have some picts on my profile if you want to check it out.
