Jeep Strokers

Why would it work because its a 4.0 but....my 258 serpentine harmonic looks 34 years old with the rubber insert falling apart. I know a 4.0 would logically fit but would it still be okay on the 258 crank ? When they break into two pieces it really sucks ! My 83 mustang did that years ago. Thought a rod came through the block.

Depends on your crank. The snout on most 258 cranks will need shortened or you will have to use a spacer to get the 4.0 balancer positioned correctly. This forum has all the info for cranks and the differences http://www.jeepstrokers.com/forum/viewt ... ?f=34&t=51