I have a set of the "AU" five spoke rims on my 72' right now and I have been looking for the backspacing on these rims. One of the camaro sites i went to had 4"1/4 on one post and 4" in another? I was wanting to put 275/60/15's on the back but from searching our site it looks like 4.5" is needed.

My other question was that the camaro site said 70-73 were one style with the spokes sitting close to the outer trim ring. The 77-81 had the spokes recessed into the rim by about 3/8 of an inch.

Is it noticable between the rims? I actually have a set of 78's on mine.

Anybody

I went and checked the bs on some early wheels and they are 4.25".

The visual difference between the wheels/trim rings is noticeable, a less visual clue is that the spokes on the newer rims are a little flatter on the widest part of the spoke. If you are not concerned about originality just make sure you have a matched set. You would be amazed at how many show cars have mixed set of rims.