Moving Rear back or Cut front part of wheel well

Your axle might hit the frame rails before it actually happens. Going over the tire a little bit like a couple inches I would say yes but trying to bury any part of the wheel might not happen unless you 4 link & full tubs.

Look at member rgreule's car. Leaf springs with a Hemidenny K frame. His car is pretty damn low and the rear quarter is barely over the tire.

There are a couple of guys with 345/50/18s which is a 14in wide tire and 28 tall. Some completely tucked and some lowered over. Doesn't have to tuck a great deal. Ill buy a tire mount and try it after i mount the new rear. The 315s are not as wide i believe. I will give it a shot and if it doesn't work I will figure it out for a different tire