Ive searched high and low to try to find another combo using a 3.5" stroke crank to no prevail. So i dont know what this thing will really do when i get it all together! It probably would spin even faster if i left the childs and albert aluminum rods in it that i originally had planned on. But then ran across the set of manley i beams and switched them out. Sure would be fun tho to spin 8500 and keep on pullin!