I have 7.50-17s on the back which are 32" tall. while I don't have much experience hauling any loads yet I have no problems maintaining speed on hills. as a matter of fact I live on a fairly steep mountain & I can start at the bottom going 55 & accelerate to 60 plus by the time I get to the top. I'll admit my way less than stock 261 certainly helps, but I had a 3100 with a stock 235 with the 3.55 gear conversion in it & it pulled the hills pretty much the same way. you guys aren't giving the old stovebolt engines enough credit. with 4.10 gears your truck will do any thing it already does only better.
