my fuel economy is pretty bad as well. I think a big part of that is how your converter stall is matched to fueling and turbo spool.
The engine seems to have an economy sweet spot around 1800rpm. I messed with the TV cable and TPS adjustment to try to keep the motor up in that range, no idea if thats doing anything yet. Certainly easier to spool in a roll-on

 

That's one of my concerns too. I noticed when I pull my big enclosed trailer with overdrive on, it locks too soon and stays locked unless I tap the brake. Also I noticed if I get into the throttle the tranny jumps into passing gear. I need to check out a thread on adjusting the TV cable and slot the tps and adjust. I put a new tps on my last '96 and it seemed to do better but this tranny in my latest '96 is much stronger. I didn't have a chance to fix my injectors this weekend because it was rainy all weekend. I was also going to wait until I get my torque plate and govgovernor springs and do it all at once since I have to pull the intake horn. I changed my fuel lines from the pump to the steel lines on the frame but I heard them ticking up by the tank so I need to replace them the rest of the way back. I already have the hose but need to drop the tank. I'd like to clean my tank and screen while I'm at it.

 

Unless your compressor puts out 17,000 psi (that's what your injection pump puts out) don't think you would do much good.

 

OD locks way too early on mine. I tried clocking the TPS and as far as it goes is 1.3V which doesnt seem to do anything to the early shift. I had to take the tps off and lock it at 1/2 throttle or so to get the shift point where I want it. Downshift still isnt quite right, but Ill take what I can get.
I may try putting a resistor across it to change the voltage at zero throttle.

 

When my truck was new I had the dealer flash the PCM for lockup at 55 mph.
Might be hard to find a dealer who knows how to do it nowdays.