What about machining the ring area of the piston down a little? Tighter skirts and looser ring areas?

Pistons are not round and are tapered.  It takes a special piston turning machine to machine the profile on the OD of the piston.  It takes a lot of trial and error testing of different piston shapes to arrive at the optimum profile.  The OEMs sometimes go through 20 or more profiles before they find the one that works with a stock engine at stock power levels.  It is obvious Wiseco does not do this much testing on their profiles base upon the ware paterns I see on the OD of the piston.  When the power level is increased significantly, the profile needs to be changed. 

I think that design of the Wiseco piston needs to be changed for the LT500.  Wiseco want about 8000.00 to make a forging die to my specifications. There is additional cost for programming and machining different skirt profiles from the handful of what they call there standard profiles.  I would probably need to charge 300.00 or more for a piston to help recover special programming and tooling cost due to the small number of pistons produced.