Hi, u can get a slightly over bored piston & jug from Rock Solid Engines. They have been taken out to an actual 70cc, not the normal 66. They come in 3 different "stages", HP1,HP2 & HP3 & u get the gudgeon, clips, quality bearing, piston & jug. I believe the piston has properly spaced bosses 2 fit the bearing properly. HP2 & 3 pistons r ceramic coated (skirt). I recieved an email off Tony at RSE recently telling me not to order just yet as they will soon b releasing more Hi Perfomance products. Cheers