Tunnel ram or no tunnel ram...

1973 400 block. Magged/sonic checked. It was Hardblocked to the bottom of the 'freeze plugs'. It had alloy caps, bushed lifter bores, 1960ish bobweight. 4.0" Crower crank, 2.1 journal 6.700" BME rods.
Wow at that bob weight, that's exceptional.