Please help!! Hi, I have a 67 camaro and I am interested in putting 18x9.5(+56mm offset with 7.45" backspacing in the front) and 20x10.5 (+56mm offset/7.94" backspacing)in the rear, C6 corvette wheels, can this be done? and how? if not whats the biggest I can go?

TOO BIG! The biggest that you can go that should work is 18x8 in the front with a 225 or 235/40 tire with 4.75" to 5" of backspace. In the rear 20x8.5 with a 255/35 tire with 5.25 to 5.5" of back space. Since lots of people have fit a 17 or 18x9.5 in the rear with a 275 tire you may be able to fit a 20x9.5 with 5.5 to 5.75" of back space with a 275/35 tire but I have not actually seen this combo in person so I don't know how tight it is. The sizes I gave you DO work I've seen it done. Do a search this has been discussed here several times. There is also a post from not long ago with pictures. When you go max sizes lots of variables come into play - like what kind of brakes and ride height. Measure carefully - both sides - buy once. Good luck.
2 pages back 1 post is "love it or hate it" the other is "here we go again...20" wheel debate" check it out!

umm...
JV69 is totaly right TOO BIG!
those tire sizes are a touch on the wide side (by like 2")
and the back spacing is even more wrong

Please help!! Hi, I have a 67 camaro and I am interested in putting 18x9.5(+56mm offset with 7.45" backspacing in the front) and 20x10.5 (+56mm offset/7.94" backspacing)in the rear, C6 corvette wheels, can this be done? and how? if not whats the biggest I can go?
You can do it with those tire sizes but the offsets on the wheels will change. Secondly, here is the rub, you must change to an aftermarket subframe and mini-tub the rear. That is the only way.

14" and 15" diameter rims are the only legal rims allowed on 67-81 Camaros.
No other diameters are allowed.

Must be a rule in Joplin. http://www.lateral-g.net/forums/images/smilies/lol.gif