Its more likely your throttle cable is "dry" and needs to be replaced. With how many times that cable moves its suprising how little its changed. I only changed mine due to a new intake setup but I was pleasently suprised when the petal was no longer stiff feeling.
You can use a shifter cable out of a stick shift fwd and make your own setup. It really depends on how creative you are. I bent my shifter rod and it worked but I pulled the trans really quickly after doing it so I don't know how long it lasts.
my setup 351w, bbk shorties, summit 2.5 h pipe. should be the same for 302 with factory headers
I said screw it and converted to a stick. I also have a 84 with factory console so it was relitavely easy for me.
change the crank sensor if its one of the last things left, if its bad it would explain why the motor loads up with fuel, the spark cuts out and loads the exhaust - o2 spike at stall
I'm half way done with my tbird, when I first got it the car came with a 67 289 4 barrel with a aod. Now it has a 351w and t-5, the car did run with this combo last summer but I took it apart to add Efi. here is some misc. pics of the fila emblems, fila seats, my dash, and the engine bay as it sits today.
where on a mustang is the relay? on the harness you changed or under the seat i'm asking to see if the fuel pump monitor wire the mass air computer wants is hooked up or not. i'm in the middle of a mass air conversion (stupid speed densidy harness) during an carb to Efi upgrade (84 fila tbird)351w 5 speed from carb aod and i'm having lots of fun with wiring right now also.
you should look into how long before your state allows that custom plate to be reissued especially now that you put it out there that in Pa. that name is open. just some food for thought