My guess would be itÆs a cast iron crank with a rolled fillet. The factory is concerned that grinding the journal will disturb the fillet.

You can buy that crank re manf with undersized journals. In most cases it works, it just may not have the same fatigue life as the original part.

Typicly cast iron cranks are not factory hardened.

Kevin

87 Turbo Intercooled Raider, roller cam, torsen rear diff, LSD front diff, lockup auto with modified converter, V6 brakes, low transfer case gears...