Brickboarders, I have a problem for you

I have an 89 244. It has a motor out of my other old 89 244 that was wrecked. Has been running fine for a year or so until now.

It has a hesitation around 2000 rpm or so that is a miss and when it occurs, it will not rev over 2000rpm or so. It is not dependent on load, as it does it in neutral and reverse (yeah, go figure). It is like it is running low on fuel.
I have replaced the following things: Plugs, wires, cap, rotor, in tank fuel pump, coil, it has a new(er) O2 sensor, FPR, and a new ECU coolant temp sensor. It has more than a 1/4 tank of gas when it does this and it is warm 90% or so of the time when it does this.

I changed the fuel pump out yesterday and cleaned out the throttle body. It ran fine without the miss with the exception of a high idle that I think is caused by a bad throttle body gasket that I will replace tomorrow for longer than usual today until I parked it and went into walmart where I came out and it did it again.

My question is, what else do I need to look at replace? I have a hypothesis that an oil leak on the back of the head only when hot is leaking on the Crankshaft position sensor and causing me problems cause it does not do it all of the time. Does that seem likely? Im going to crawl under it tomorrow and take it off and clean it to see if that helps. Any other suggestions would be appreciated.

Thanks.

Whitt