alrite folks here we go, i have a series 1 that im going to build the engine myself ive changed pistons etc myself before but ive never had a block bored out before so im not sure how much all you 2.1 zvh folks exact bore is & do you buy pistons the exact same size the bore is, im not boring it out myself i just need the measurements to give to the machinist & the size pistons i nead to buy... thanx