Figure out about where you are at power wise, call the good folks at Southbend and go with their recommendations, just be honest with what you will do to the truck and they will do the same. When I called I told Peter that I wanted a clutch to drag race, sledpull, tow, DD and just generally abuse, he laughed and started asking questions about where I wanted to be with the truck power wise. Once that was discussed he named off a clutch. Installed the 12CB 3600 this week, we'll just have to see how it goes, but so far I really like it.