I have a 63 406 that's running the stock lowriser heads and tripower induction. A cast 428 crank with lemans rods hold the bottom end along with the block crossbolted. My 406 block has the
oil pressure relief valve and larger
oil passages like the 427. Kind of a poor mans 427 if you will and it's not costing that much to build which is nice.....well not as much as a sideoiler anyway LOL. G.