Double check that you are using the correct cylinder as #1.

Been there done that.

Cam is hydraulic roller with stamp steel rockers . I did tighten the rocker arm nuts all the way down and to about 20 inch pounds. Could this be the problem? Do you adjust rocker arms on these motors? If so how?

Im not sure about Your motor "I work on cars" but most GM car motors are ajusted 0 lash then half to three quarter turn,

Half the valves can be adjusted at top dead-center. The other half of the valves can be adjusted after 360 degrees crank rotation. The manual will tell you which ones to adjust. Start by tightening nut down with one hand and socket and the other hand using your index finger and thumb around push rod twisting it until you feel slight tension on the push rod then tighten it down 1/2 - 3/4 turn. After this, you should do a compression test.

GNJ,
Did you put the distributor in base timing mode before you set the timing?

Dave

Just crank them down to 20 Ft. Lbs, no matter where the cam lobe and lifter happen to be? This does not sound right to me. But I've never been inside that new a V6.

I did not put in base mode. How do you do that? I had the timing light on it while running and at 1350 rpm the timing did only advance a few degrees before it started to act up so probably not the main issue. Any other ideas or things to try? Anybody know of a way to re-check cam timing without tearing the front of the motor apart?

If I'm not mistaken, it should be a Thunderbolt V system.

GNJ,

Try this before you do anything else. You have to set the timing in base timing mode. This may be your entire problem.

Dave

Sorry, I do not have access to the timing mode file being posted since being a basic memeber. Can you or someone email it to me at [email protected] or copy it into here?
Thanks so much.