I just made a thread about the primary puller we make here, a real heavy duty unit. Works with the stock, or STM.
When I install a clutch, I always lap it it, then be sure & remove all the compound. I use lacquer thinner, wash the crank off with a clean, dry rag, then clean the inside of the primary with a liberal amount of lacquer thinner, then wipe dry. Do it as many times as necessary to get all the componud out.
When installing the primary, I always torque the bolt, then make a short run, come back & torque it again, it will go down some, then do it again. Keep doing it, until it stays torqued, then you're good. I've put 400 crankshaft horsepower thru the crank taper, with no slippage, with this system of installing.