That's just it--I'm not sure what the chain could be hitting, but it is the chain. Short of running the engine with the valve cover off (not a good idea), I'm not sure how else I'll be able to figure it out. I've owned over 30+ Toyotas and have had several engines rebuilt (=lots of experience with broken chain guides), but I've never had one do this. And of course, it has to occur on my "baby" that I've owned for 15 years and don't ever plan to sell.

The engine was a complete rebuild. While the engine wasn't wasted, I figured since I had to have a valve job done and replace the timing chain, I might as well just yank the whole engine. I find it is often easier just to do that rather than try to take everything apart while in the truck.

All of the typical internals were replaced, including larger pistons, bearings, rods, gaskets, and timing chain set.

I was doing some research after I posted last night, and I read another recent post about a timing replacment gone wrong, and in that case the wrong length bolt was put in the oil pump and was seizing up the tensioner. I don't know if that's my issue, and I don't know how to check for that short of pulling the tensioner out and inspecting it.

Since this machine shop put the wrong cylinder head on my engine in the first place and didn't even know there were different style 22Rx heads (even after I explained it to them), I wouldn't put it passed them to screw up the bolt sequence. But again, I don't know if that's the problem.