EFI or carb. ?

[krepe]

I currently have a 89'Mustang GT.I have a 83' 351 Windsor(rebuilt).Forge pistons(40 over) 24lb. Injecters,stock heads,stock throttle body(65mm. i think),3-core radiator,180 thermostat,gear to gear timing,headers,no cats,3" pipes all the way back,cam,racing clutch,K&N filter,Edelbrock Performer RPM upper/lower intake.
The computer in my car is from a 302,and since i have a 351 Windsor ppl are telling me that,that is why my car will not perform down the track,that I should be in the mid-13's.So my main ques. is.
1)Buy a computer for this engine?
2)Should I tear that EFI bullshit off my car or should i pop a carb. on it?

best 1/4 mile = 15 flat
weight of car = 3,450lbs.

thx guys, -krepe-