Okay. Riddle me this:

I get into the nitty gritty. Spin things around a dozen or so times, none of the timing marks line up for sh*t. Say what? <img src="/forums/images/graemlins/scared.gif" alt="" />

4G63 - set belt to marks, spin it around a couple times, make sure marks are still good.
420A - set belt to marks, spin it around a couple times, make sure marks are still good.
G54B - set chain, spin it around a couple times, nothing lines up. Spin it some more, still don't line up. Spin, spin, spin, spin, spin. Marks never line up again. Pull cam sprocket bolt, pull guides, pull oil pump and balance shaft , start the eff over again. Same thing happens.

I decided to leave the balance shafts in after all. Had one of the chain guide bolts in the oil pan. Two of the front case bolts were completely loose, just too long to fall out (even with blue Loctite on them).

The deeper I get into this, the more I realize there's no friggin' way I could have timed it wrong with the balance shafts out of phase. When #1 is TDC, both balance shafts are pointing downward. Per the FSM, the mark on the lower/left/oil shaft is about 7 o'clock and the upper/right is about 12:30, with the crank sprocket indexed on a key. I've tried to intentionally time the balance shafts out of phase. Can't do it.

So, while I put this damn thing back together again, what theories does the group have as to why, as the tach crosses 2000rpm, the vibrations get so bad, the mirrors are useless, and half the sheetmetal on the truck buzzes? This vibration goes away as you pass 3000rpm, is all but gone at 75mph.

I've just wasted a Saturday, it seems. <img src="/forums/images/graemlins/cheers.gif" alt="" />