What rpm does the car run to?

Right now from the exit of the corner it starts around 3000rpm all the way to 6400rpm

poorboy, without a custom tune, bigger injectors will likely do more harm than good. Adding a little more fuel by upping the pressure (with an adjustable pressure regulator) could help, though. I assume you are running open exhaust, but are you using a manifold or header? A header may help the torque coming off the turns. If the throttle body from a 2.5 ranger is larger, that may help breathing as well.
If the Mustang still has the 7.5 rear end, I have my stock 3.31 gears around here somewhere (close enough to 3.27, me thinks). You can have them for the price of shipping, provided I can find them.
I think you may have better luck finding your answers on one of the big Ranger forums, as there are probably quite a few modified 2.3/2.5 Rangers out there.
What sort of mods are you allowed to do with the intake/exhaust?

very nice of you and some great ideas to boot. Two thumbs up

If you find the gears let me know and thanks for the info im going to check out the ranger fourms

there is no real way to turn the stock computer. You are forced to either got to a stand alone or convert to carb. Can you gasket match the intakes, and heads? Can you clean up/port the heads? Light weight flywheel/clutch set up? aluminum driveshaft? If it is a 1990 what about swapping out to a ranger cam. stock for a ranger can't remember what years and stock for a 91-93 2.3 mustang.

more great ideas, you guys are smart for sure

holy that's strict... that's why i run GT class in solosprint.

gears would help a lot, fresh rebuild with new internals (OEM sizes), suspension if allowed, and some good tires :tup

I've turned this place upside down looking for those gears, and can't find 'em. I will keep looking, and let you know if I find them. FYI, all V6 mustangs from 05-10 still had the 7.5 rear and 3.31s.
johnny5 has some good ideas for you, as well. It would be nice to take a good look at the rule book... Sometimes what is NOT there can help you most.

couple of other things.
-Degree the cam, the best you can while maintaining the stock cam gear. A lot of trail and error since the timing will change a bit after turning the engine over a couple of times. so just keep adjusting until its where you want it after it settles.
-Windage tray/oil pan
-better Ignition
-knife edge the crank
-under drive pulleys
-esslinger has a light weight billet water pump
-exhaust manifold/header

you can also play with head gasket thickness and milling the head to get to the 190psi limit.
if you are going to stay efi, find/make an intake and tb set up that fits your powerband/application

you might not need to rev it that high. My 4 banger at a dyno day after some very minor work (i.e cam, cold air, exhaust) made 94rwhp at 4300rpm.

might be worth emailing esslinger or bo-port (but bo-port does more turbo stuff) and see what they can recommend.
maybe see if there is a rocker arm with a different ratio to get more lift even though it is a stock cam.