I bought a 70 318 once for a core with a rod knock for the forged crank, opened it up and it had 4.070 bore TRW forged 340 pistons in it. I still have the block under my shelf as the bores still look great, I just can't convinve myself to put it back together seeing how the normally 165 # block now weighs 122# and the bores sound like glass when I tap on them with my fingernail.