I installed one in a 46 1.5 ton and it works like a Hank. The one I'm useing is a three speed under straight through and over. Top speed in under is about 30 mph I have' nt had the nerve to go to the max in over probly some where around 80 or 90. I think this would be a good fix for most people wanting overdrive instead of useing the light weight I want'a break alum. car trannys.