I am sure this has been done before, What's the widest 15 inch rim and the biggest tyre that I can fit under the rear of my unmodified 57 Fairlane rear wheel wells
Always happy to see a first post from a member...welcome.
I think you'll find the info you're looking for in the "wheel and tire sizes" section further on down. look for a thread title 8's x 15's and clearance...." by Limey57
Rich
http://57fordsforever.com/smf/index.php?topic=2640.0