YHM has released a new piston that has a "universal thread adapter" that screws in to the base of the piston. The pistons now come in a "one size fits all" configuration where you can buy extra "universal thread adapters" and swap them out of the base of the piston IOT configure the piston to whichever thread you need.
YHM's Universal thread adapter: http://yankeehillmachine.com/store/product556.html
YHM's Universal thread adapter: http://yankeehillmachine.com/store/product556.html