setting distributor (cam retard) on 5.7 vortec with aftermarket distributor

[munly]

Just another note...when I brought the truck to the shop it was at -8. When they adjusted the distributor -6 was as close to spec as it would go. I was at the shop a few months back for the same issue and the timing as -13 and after adjusting -6 was as close to spec as it would get. I've watched a video on YouTube where a 5.7 vortec was -13 and rotated to 0 without moving the distributor one tooth. I don't understand why my truck's timing won't get any closer than -6. Is it possible that it's a camshaft position sensor or a crankshaft position sensor? It should be able to go from -13 to 0 with a very slight rotation of the distributor. Any ideas? Thx.

 

[Whipped96]

I replaced my distributor with this one, http://www.ebay.com/itm/320605212568?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I reused the factory hold down and was able to adjust mine from -10 to 0 with no problems.

 

[BOTTLEDZ28]

The distributor doesnt have to move much to change the timing so dont think that you have to rotate it 1/4 of the way to change the reading. The hold down bolt is tightened down and the truck is started and brought up to temp...somewhat. Plug the scanner in and then slightly loosen the hold down bolt to allow the dizzy to turn with a slight resistance.