EFI or carb. ?

[Unit 5302]

Um... am I the only one that's noticing 1983 351?

In stock form that's good for what? 160hp, maybe?

You need heads for sure.

What intake is on it? The 1983 351 wasn't SEFI, and the 302 intake won't fit onto a 351. What cam do you have?

A stock 89GT Hatch weighs 3100-3150 lbs, do you have a vert? Or is that the race weight?

The computer shouldn't be causing the problems. Is you MAF calibrated for 24lb/hr injectors??? If not that's obviously a big problem.

Here is what you should have to run a 351 on SEFI with a cam.

77mm MAF, 75mm T/B (stock is 60mm on the 89GT), adjustable FPR, 190lph fuel pump, high flow intake (TFS, Edelbrock, Holly...ect), and some good aftermarket heads. Again, TFS, Edelbrock, AFR, ect...

Sounds to me like your combo may be horribly mismatched, which is why you can't get anything out of it. I'm guessing the heads are holding you back HUGE time.