tire sizing

[fuzzman]

I want to put 15 by 7 on the front and 15 by 8 on the rear on my 66 how wide of a tire do I dare buy?
I'm using Magnum wheel with a 4 1/4 and 4 1/2 backspace.
I'm hoping to use a 65 series tire ThanksBeer

[honcho]

4-1/2" back space on rear your can go 245/60/15 8" in rear- 5" backspace you can stuff a 255 in rear,been there and done that