It's not really a 5th gear versus 4th gear issue, it is a Lockup Clutch issue...no matter what gear it may be in.
When driving with the clutch already locked up, the SLIGHTEST pressure on the accelerator and the thing will unlock! That's what I'm trying to change. I want to be able to go almost WOT and have the clutch stay locked up.
Hydrashocker, if you could find out more about the fella that you know of who did this, I would at least like to learn what he did to see if I want to try it. If his solution looks to radical, I'll pass. I have already ordered the Transgo shift kit but it has not arrived yet. As for your other suggestions, they sound interesting but I don't know where to go. For example, where can I get the PCM flashed?
I've done some reading here about the TPS Mod and there seems to be varied opinions as to whether it is worth messing with.
I appreciate any additional information.