well if its down on compression, your gonna need at least one piston, some people still have standard pistons forsale, but you need to know what number the piston is, there is a number next to the bore when you remove the head. and rebuilding a engine doesn't mean it 0 miles, because you still have the original crank caps, even block, you would have to replace the big end and small end bearings, thrust washers, need a new head gasket kit, and one piston and new rings for all pistons. i think i rebuilt mine for about 350 a couple of years ago, and most of the parts where genuine toyota, apart from the second hand pistons. hope this helps jake