Mine being a 4wd with 4.56 gears that came stock with 33 inch tires. In my experience the truck would run like a bat out of **** if I shifted from 2nd to 3rd at 4000 rpms, that really launced and carried the momentum for the 3rd to 4th shift and had no problem keeping up with a friends 96 GMC 350 with fuel injection. Things will be different now with the 478M, I made one mistake in the build not realizing until later that the hoollow stem sodium filled exhaust valves snap from over reving, those are going to have to come out.
