ok, so the it's lockup. 4th gear IS OD, lockup is on top of that (you still need something like this for the carb geometry
http://www.jegs.com/i/JEGS-Performan...57301/10002/-1 )
I am not the expert here. I have done the lockup thing with 2 700r4s (my vehicles), both with carbs, one with a TCC kit (didn't really need), one by just rewiring, both with on-off switches. I couldn't quite follow what you did with rewiring. what sort of 4th gear pressure switch did you have, 1 prong or 2?