I had 15 x 7 Auto Drags on the '67 in my avatar. Wanted to run the 4 7/8" bs but my slicks would have rubbed the springs, so I went with 3 5/16" bs. Didn't want to buy the offset shackles and move the pads because I planned to do a mini tub and figured I'd live with them sticking out even with the lip until then.
I think on the front you're definitely going to want the 4 7/8" bs as the front track on A-bodies is a little wider.
