All of those engines have too much power for a 7 1/4. You need at the very least an 8 1/4 axle.

A friend of mine had the later c-clip version in a 93 Dakota 2.5 I4 and broke it. Also had another friend who had an 88 Diplomat with a stock 318 and broke it. Everything about that axle is WEAK


'70 Duster 470hp 340/T56 Magnum/8 3/4 3.23 Sure-Grip