DaveC,
IMHO, grinding parts on the bow is not the best thing to do (especially cams/mods), and it voids your warranty, but people do it all the time ...:shrug:
Of course now half-inch mods are available, but they won' t fit the 2002' s.
That said, I think you probably set the stop in a good position. Just have someone draw it for you while you watch the cam rotate and make sure that the cable doesn' t fully bottom, over-rotate, and then the stop hits the limb. It' e easier to show than to explain. But if you take the stop out and draw the bow you will see when the cable fully bottoms then turns at a sharp angle as the cam over-rotates.
As for lengtheninig it...as long as you adhere to the advice I posted from the manual you should be OK.
Personally I' m the opposite. I set the stop pretty short at around 60-65%% letoff. I just shoot more accurately that way and the drop into the valley is not nearly as abrupt.