Still trouble shooting front end noise since timing chain install. Thanks to EB, I've ruled out all the common mistakes. I just pulled the oil pump. The "brand new" oil pump drive spline has severe wear after only 50 miles. There's metal between the teeth, and my educated assesment of the clearance between the oil pump drive spline and the oil pump gear is about .015" to .020". This does not seem right to me. The rest of the pump is tight (well within maintenance manual limits). I just stuck some .020" safety wire between the two gears and it was tight but it fit. Has anyone had any experience with this?

well I'm going through the same problem myself.I had to replace the tensioner because I torqued it to much and the shaft was bound up.Most of my noise is gone except when I shift gears, once the engine reaches the rpms to shift it does the rattle or I can play with thottle at highway speeds and make it do it.I've looked at everything when I had the cover off and checked ok there was no wear on anything cover/oil pump drive/crank gear.It almost sounds like the chain is slaping the metal backed chain guides but they looked brand new and I've been driving the truck for a year.I feal your pain,it's driving me nuts if I can narrow mine down to something I'll let you know.

Yeah, I found a few small things that were making some noise, but this noise has been present since day 1 of the inital time chain change. It's always there in all rpm ranges and changes pitch with rpm. Even at idle, you hear it kinda reverbing in and out, it's weird. I changed all the tappets in my rocker arms, and it quieted the motor sigificantly. I have faith, I'm going to whoop it.

Wow.. that looks bad.
When you installed the oil pump there are two guides that center the pump.. Were those installed?

Yeah, the guides were there, and the pump didn't leak. Oil pressure normal, everything normal. There just seems to be alot of slop between the two gears. Everything was installed the right way. I was hoping that I had a gear in backwards, but no, that would have been to easy.