What crank 1970 318?

In 1970. the balancer changed part number because they moved the timing slot to the driver's side. The new part# is 2951673 and is listed for all 318's (cast crank) and 340's (forged cranks) regardless of transmission. They still swap back and forth with the earlier balancer if you remark the timing slot depending on which timing cover and indicator you use. In '72 they changed the balancer once again by going to an even bolt pattern for the pulley instead of the early one with one bolt offset. Simply slot that one hole with a file and they will swap with the early balancers too along with the other caveats I mentioned. Mopar even made replacement crank pulleys with the slotted holes later on so they would fit both applications.