will ap1 rears work with a 20mm studded spacer?
and will a ap2v1 rear work on that with a 255 tire?
lowerred just over and inch

 

Yes the rear tire will work with 255; the CR's came stock using a 255 tire for more grip.

 

If you mean a 255 tire on the rear with an AP2V1 rear wheel and a 20 mm spacer, then you're going to need more camber, a fender roll and to trim the rear bumper. I had to do all that to fit a 245 on a +45 wheel (same effective offset as an AP2V1 wheel with a 20 mm spacer).

 

wheel width comes in to play as well. a 17x8 +45 is going to stick out a half inch less than a 17X9 +45 will.