1971 GMC Truck MAJOR timing problem

Trucks timing is off and cant seem to get it on. Has new plugs,wires,timing chain and the distibutor is good. We have tried two distributors just for assurance. Had a friend help me try to adjust the timing. Go it to TDC and re-sat the distributor got it pointing at the #1 and still nothing. Im not much of a mechanic but my friend has been working with Chevy engines for years and he is stumped. Any help would be greatly appreciated. Its a crate engine with only 20,000 miles if that makes a difference. Thanks Nicholas

"still nothing", what does that mean?

Thanks for the reply. Sorry it will run rough then back fire and die. Flame threw the carb also.

It is out of time, recheck the order of the wires in the cap and rotation naturally, bring up to tdc on # 1 you can feel compression thru the plug hole, get it on the timing mark on the damper, this assumes the cover and damper are matched sets here, , set the dist at #1 on the cap, assuming the cam is timed to the crank, that's it.

How can you check if the cam is timed to the crank. And if you cant check how do do you do it?