I thought I did... The ignition timing is about 12 deg BTDC, the manifold vacuum about 10psi.
It runs better now, but it still tends to get into this hunting idle mode - but more often than not, it settles.
Maybe more importantly, the short term fuel trims never go negative.
True about the timing cover, but - before I dove into it, the valve timing was way off because of badly worn cam sprocket, and both base idle and MAF bias voltage were tweaked before I bought the truck. MAF read 3.5V at idle.
Part of the issue is the 170F thermostat in this motor. It is too close to the 14CUX decision point on closed loop/open loop operation.
I totally enjoy the truck running super cool in the desert heat, but I may still bump it to 180F unit.