Some Questions about tire fitment

[83Monte]

I have a 83 Monte carlo project that I on building up and was wandering that scince the Regal and The Monte are basically the same if you guys would know what size tire I could fit under the back with 15" rims? I would also like to put skinnier tires in the front but not to skinny. And finally what backspacing should I use? Sorry about all of the questions and thanks for the help?

 

[c&cgn]

On a 15x8 rim you can go with a 275/50/15. some guys put those on a 15x7 but they do bulge a little. BS is usually around 3.5" - 4". My 15x8's with 26x10" slicks are 3.75" and work perfectly. HTH

235/60/15 works well up front.