The pulley is supposed to be the reference mark for lining up the belt. And as you've noticed, the belt marks wear off, and also once the engine turns over once, those marks are in a different place.

Line it up with the crank pulley/harmonic balancer and the long 0° mark on the lower timing cover. Now, it IS possible for one of these balancers to slip, or rotate the outer ring vs. the inner ring , due to the rubber layer separating.

If there is some doubt about the integrity of the pulley, remove the #1 spark plug and (gently) put something long down inside there to feel the top of the piston. Rotate the crank back and forth till you feel the highest point in the travel of the piston. If it does not agree with the timing mark, you may want to get another pulley.

Good luck with it!
--
::: Rob Bareiss, New London CT ::: 92 244 ::: 90 745GL ::: 90 745T ::: 84 242DL ::: 90 745T Parts ::: Used to have : 86 244DL, 87 244DL, 91 244, 88 244GL, 88 744GLE, 82 245T, 86 244DL, 87 244DL, 88 245DL, 89 244DL!