for ball cups I always replace the associated ends with RPM ends .. on the TC3 you have to shave the tops a bit to get wheel clearence but the beefer ends are worth it ... I shave mine with a dremel tool and a standard (#420) cutoff wheel .. I just go down the thickness of the wheel ... and in the diameter of the wheel on the arbor and it works wonders for up to 28mm foams .. if your running outdors with 30mm reas you will have to go a bit further .. but for 28's on carpet .. its perfect .... hope that helps ... also upgrade to lunsford Titanium Turnbuckles for a better turnbuckle at about the same weight.
for the droop measurement I always do mine on the arm with the shock off and the C-hub or rear hub off .... but thats just me .. you can do it with everything on but I always take everything off .. all the associated setupsheets are measured from the arms ( per a factory driver .. I asked to make sure )