89 Mustang w/Haltech

May not be the answer you want to hear, but take it out sell it, and put the Harness and computer back to stock.
The stock computer can handle those mods easily and effeciently, but if you want to tweak the computer more, which for some unknown reason people want to, even though the stock comp is plenty good, get one of the better known DIY systems like the PMS or tweecer.

And just so you know, without a dyno or wideband the percentage of chance that you get the setup right with a standalone setup is near 0.
It's tough enough finding a shop that knows what they are doing with the accel DFI standalone system, you are really rolling the dice with a haltech on a domestic car.

I just saw this post this morning, looks a little old. I ran across it while looking for ECU plugs for Ford ECUs.

I'm a haltech certified tuner, send me an email if you've still got it and need some help.

john@sixsigmadyno.com