I have a 400 block, 4006530-300-3, built during the day on 10-15-73. The block is half filled, bored 4.380 for 0.30-over 440 Pistons, and freshly lined bored 2.943 for a 440 crank. The mains are aftermarket and I believe have ARP studs. The block has one heil-coil. The mains was lined bored on...