I have a 95 3500 2 wd Cummns 4:10 gear. Yea the old 12 valve. 18 empty and 13 loaded. IF it h54 3:54 gears it would get 5-6 better. I have a bud that gets free ATF, strains it thru a paint strainer, runs his old 12 valve!! ha I use mine just for pulling. Do I need it anymore at 74? Usually not. But when I do it pulls anything I hook it to!