If stock (or stock replacement) 400 pistons and rods and stock (or stock replacement) 383 pistons and rods, the cranks will interchange if one keeps the rotating parts together. So cast crank with cast crank damper and TC/flywheel, forged crank with forged crank damper and TC/flywheel.

The engines used exactly the same connecting rods and the stock replacement pistons are the same weight. Mopar engineers were champions at making things work with a minimum of fuss. I bet the early 400 cast cranks and the late 383 cast cranks were the same casting #.

R.