Well, oddly, even though I have a Centerforce clutch, I don't know that I actually "need" anything beefier than stock. BUT - that's probably because I have the Calmini 4.24:1 transfercase gear set - as low as I am geared, I could probably get along fine, on 50 HP - maybe even 25 HP. Obviously, not at highway speeds, but when it comes to crawling on the rocks, gearing and lockers make everything else look simple!