SS - I've been told that an 8.2 inch rearend has an 1 1/8" pinion nut and an 8.5 inch rearend has an 1 1/4" pinion nut. Any you guys out there think otherwise. I'm interested also, because I plan on putting on in my '67 convt. I got this info from a rep of Richmond Gears. SS - also Chevy only put these in Chevelles in late '72 models, then in '73 they were standard. They may be longer than the rearend you currently have, so check the dimensions of your spring purches and you can offset the axle length by using a different wheel offset. I plan on doing the same. Good luck.