The 351 will last you a long time as long as you don't run it wide open all day long. It will outpull a sbc any day of the week. we had a fleet of them in a lumberyard where I worked. One two ton had the Roadranger tranny, 5 speed overdrive with 2 speed rear end. I was able to haul 10 tons of sheetrock at 80 mph (as high as the speedometer went) without any problem. I would guess I had that truck at 100 empty.
