I am trying to figure out how to raise my gear ratio in my "chunk". I currently am still running the original differential. And to call it a three speed is not really true in today's world. It blows the tranny gasket if I run 50 mph in it. it doesnt like to get above 45. i have to be able to run it on the road but i keep getting different stories from my truck guys. one says it needs a 3.08 the other says a 3.50 or a 3.70. Help! Its a cruiseomatic tranny. I need to order parts and get this done but cant. Please post some input for me. Thanks guys!