my lifan 140 is stock atm but i just orderer a irk n oil slinger just waitn 4 it to turn up a uni filter wat i want to no is can i buy a hc piston 4 it can any1 put up a link of sumwhere that sells em will just changing from my stock piston to hc will it make much diffrence n can i just put it wit out doin any outher mods beside the irk n slinger like will i need a new cam to run a hc piston thanks any help apprecaited