i would first thing take it apart, you don't know who did this. and if it's a stock crank you gotta gear it much taller, those kits love to explode, if not build correctly.
got a piston here i can machine for ya.
exhaust| cooling holes | transfer
and maybe trim the skirt for more intake timing, but if i remember they blowback pretty bad already, if it is a true Tccd the piston crown sucks and dentonates easy without a custom head (squish)