2002 5.7 timing issue

[typhoon917]

Hi, I hate to come out of the box on my first post and ask for help but I've hit a road block and need to ask I have a 2002 2500 with a 5.7 gas that I don't seem to be able to get right. In starting, I full rebuilt the engine and the only original parts are the block and head casting, and the crank which was cut .010. I'm figuring someone will drive this to my funeral, hopefully in 50 years or so, but I've got an issue to straighten out. It starts with a light tap and runs at a cold idle about 750 RPMs and warns up to 625 Rpms with a solid idle. It drives smoothly but after I shut it down (after 100 miles or 10)I get a[the dreaded P0345 but both the crank sensor and distributor are new. It's running at +17* at idle, no nickups or burps and when I try to reset the distributor back a notch, it still shows +17*-and further back and it won't stall. Is this a function of the "computer relearn" that I need to have a dealer do? Am I missing the timing mark ? Am I crazy??? I know the distributor needs to be set a 0* +/- but I can't find it. The tining chain and gears are new, I set the distributor mechanically on the stand and it started on the first tap once it was in the truck. I've rebuilt dozens of engines and I've learned-I HATE COMPUTERS!!!! HELP.