Suggest U call Truett & Osborne and order a set of there torque monster stroker wheels for knucklehead. This rather then go to the trouble of adapting UL wheels to knuckle cases. You get lots O Tork and can go up to over 96" depending on the barrrels U use.
Remember however that knuckle cases are somewhat fragile when you start pumping them UP. But have been informed that S&S makes new
knuck cases with MSO plus stroker knuckle wheels, I think that is what FHP is using for there new mfg'd Knuckles.