THIS!! I have sonic checked 3 360 magnum blocks and the thinnest thrust was .190, down low close to the mains. along with the roller cam, .020 shorter deck, and the fact that the deck on all 3 was square within .003. The oil passages to mains and pump are also already big, no need to do that step. 4" steel crank and eagle h-beams go in with a small eyebrow notch. Only bad thing I found was main bore diameter being to the high side of spec, but still in spec. Even the chevy machinists commented how well machined, and thick they are compared to a chevy.