You only get a lower first and second gear. GM sm420 is 7.06 first and 3.58 second, GM nv is 6.34 first and 3.34 second dodge and late gm is 5.61 first and 3.06 second. The 3.34 is nicer off the line. all four trannys have the same 1.7 3rd gear. If you still like the 3.06 2nd I would go with a mid 95-up gm nv. It uses the same 1.125 10 spine input as the sm420 and the imput is the same lenght. The dodge diesel,V10 has a larger and longer input shaft. You would have to get a custom clutch made for your small flywheel and make a 1inch adapter. A dodge v8,v6 nv has I think a 1.075 10 spine input. you could use a ford or dodge clutch with your pressure plate. still need the 1in spacer.
