Nine times out of ten, Chrysler didn't use crank bolts on slant sixes. A few had them, but the vast majority did not. However, all the cranks are drilled and tapped, so you can clean the threads out and add a bolt. Makes it easier to turn the engine. 3/4" x 16 by about 2" with a thick flat washer should do it. Blue locktite and torque to about 60 LB FT.