1978 400 crank question.

Happened again just this afternoon. Let a guy use an old Chrysler Newport with a 400 in it for a demo derby. Told him the only thing I wanted back was the 400 engine. Came by today and asked if he could just keep the block if he replaced it with another 400. He had bought a 75 3/4 ton 4x4 pickup with 4 spd trans and a 400 engine. Yep, I swapped him and got another 400 with a steel crank.