Yes. The tire will fit on the rim (BFG says a 7" rim will handle a 255/60-15.
The question is will a 245/60-15 fit in your a-body wheel well? I tried 255/60-15 on cop car wheels in the Demon with BBP disk brakes. No go. I called Stockton wheel who recommended 235/60-15. It works, but just barely. When it's tiime to replace will go smaller.
