Thanks for the responses.

Some answers to questions:
John
TP linkage is the original 3 segment linkage illustrated/described in the FSM (picture attached). Moves fore/aft easily and doesn't bind. Return spring is in place and returns the linkage to full forward position after moving rearward. Literally only drove the car a few times before I pulled things apart as I unexpectedly stumbled upon an engine issue. Only thing I noticed in those drives was it wouldn't drop down to 1st even at slower speeds when it had already upshifted out of first (no 2-1 downshift), but did start in first off the line... didn't 3-2 downshift at higher speeds (learned it does have the part throttle hardware in place when I disassembled the VB)... at WOT it shifted earlier than I had hoped ~4200RPM. Other than that it operated/drove/shifted perfectly fine. As I am new to this in my reading (after pulling the eng/trans) I figured the lack of downshift was related to TP adjustment and the low shift points at WOT was likely related to its calibration for original car (c-body). Figured the former would be fixed by adjusting linkage upon reassembly...

Mike
The TP setup was adjusted precisely as described in the FSM. When it wouldn't upshift I then shortened the top segment another 1/8 (3 turns) and then 1/4 inch (6 turns) as from my reading this should cause EARLIER shifts. Thing I wasn't sure of was if these types of changes are significant or not (didn't want to damage anything). I read the Munroe 727 book as well as the FSM for troubleshooting. Seemed like I was at the point that dropping the pan or doing pressure checks was next... As I am new to this figured I'd ask before pushing into the unknown. trans has not been hung on end...

Stumpy
I have checked fluid level repeatedly while warm in N on level ground and the level is at full. Believe I have about 8.25 quarts in it right now. From my reading the amount of ATF must vary quite a bit based on the torque converter. I was nervous this was the problem, but as I said the level is up to the full mark and the dipstick appears to be the correct one. I recall from having it apart that the bottom of the dipstick sat just below the mating surface of the pan (maybe an inch or so?). Fluid/filter are fresh.

Next step
I will disconnect the linkage at the TP lever, make sure the lever is pulled full forward, and see if this gets it to upshift under throttle. Will quadruple check fluid level. I will do this before investigation anything related to the governor as that will be tougher/uncharted territory for me.

If anyone else has any suggestions let me know. Won't be able to get to this until tonight at earliest or possibly tomorrow. Having a 3 and 1 year old as well as a full time job make it tough to find 15-20 free minutes of time.

Thanks for all help so far.