remove dist cap and turn the engine over via large wrench on harm. balancer nut. once you see the rotor turn, stop and go back counterclockwise....if it takes a while before the rotor starts to turn the other way, you have mucho slacko in chain. I just replaced one on a 258 2 days ago.... If you pull the cover at all (even to just inspect it, go ahead and replace it.) If you have a timming light, you can see if the mark jumps around several degrees.
1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
1986 TJ-7 Trail Jeep project in the works
2003 Inca Gold TJ Rubicon