Unexplainable Transmission Stutter... help?

Try what @CudaFactHackJob recommended.

Disconnect the Lokar cable from the transmission. Tie/ wire back the throttle pressure lever on the transmission all the way back. Try driving the car.

That will tell all.

When he tightens the TP cable, it moves without the shudder, but won't shift from first gear. Wiring it back will likely result in the same..

As @TrailBeast mentioned, that makes it sound like a pressure issue which could suggest a couple things.

Doc, you're on the right track with the pan off. First look at the pan and see if there's any parts, glitter, sludge etc. The filter looks pretty average right now. If the pan doesn't have a ton of garbage in it, next step is to remove the filter and take note of whether it's tight or not.

Once that's off, you can see if the valve body (transmission brain) is loose or not. Once you get that far, it's time for more education as far as how to remove the valve body and do some additional diagnosing steps/checks.

The cam change and other work is probably unrelated to this issue... Sometimes stuff just happens with bad timing.