[84LX89GT]

You just bought one of the slowest vehicles ford made in the late 80's. With 88 horsepower and 135 lb/ft of torque, the 2.3L isn't inclined to get out of it's own way. I have no idea why you sold a 5.0L to get an auto 2.3L and are worrying about performance
All the cheap mods to apply to the 2.3L.....if you're lucky you may squeeze as much as 100hp out of that puppy
I'd start by gutting the cat, colder t-stat, and if you really want to buy premium gas then advance the timing. Also you can pick up gear sets for the 7.5" rear axle for dirt cheap, especially from junkyard rangers which most have 3.73 or 4.10 gears, which would help alot. You can also take the intake tube off, and using a knife, cut out the inner diameter of the muffler which restricts the air intake (it says ford and is big between throttle body and air cleaner housing). You can also cut the bottom half of the air cleaner housing off if you feel like, since that's cheap also. Later rangers also have a header stock, which you can from what i hear install in your car. If you really feel like getting fancy you could buy a higher stall converter and shift kit to help keep the engine pulling instead of lugging, with gears this would help quite a bit.
I don't know how much nitrous you can use on a non-turbo 2.3L block, but the turbo 2.3L's regularly see about 14 lbs of boost easily. You might be able to run up to a 75 shot of nitrous before things start to melt and come unglued, but don't hold me to this.

Good luck,
by the way, my 5.0L gets 18mpg city and i had a manual trans 2.3L that averaged 21 city.....i'd much rather have a 5.0L but that's just me.