I have 255/70/15's ( on 8" wheels ) on the rear of my '65 C10 step side ! Previously had 275/60/15's on rear but they were really close to fender ( inner & outer ). I have seen the size tire you are asking about on the rear of similar trucks but they had little clearance ! Don't really know but doubt they would fit very well on the front .With that size tire on the front , power steering would very much be a necessity !
