how well, will 18x8's with 5" of backspaceing fit a 78 Camaro.
I am thinking that is to much backspacing. And I think I need 18x9's on the back.

 

Here is a shot of some 18's on my 71 It was 5 or 6 years ago when I got them so I am not for sure on the size? At the time it seemed like they are all made for later model cars with wider rears so its a trick to find one! And its all in MM
I am thinking these were 18x9's and I will check the back spacing this weekend for you. I wish they were a little bit further out I think I can get another 1-1/2 out? I may build a 1 spacer and longer studs? Not the best way but its just a toy that doesnt see lots of toture.

 

cool.... yes I want mine father out.

 

This helped me pick rims and tires
2nd Generation Camaro Wheel & Tires Fitment Chart