This may sound a bit archaic , (as I am ) , but over the years I've found that , older Triumph , BSA's , HD's and Guzzi have all responded well to
what was referred to as a smooth sliding fit at the machine shops . My present Le Mans 2 with 89mm Wiseco pistons and new fitted pin bushings
are still quiet after a 1/4 century and well over 100,000 kilometers . Peter