If you don't have an adjustable fuel pressure regulator you will need one. Set the pressure to around 38-42lbs with the vacuum line off. If you already have one, what kind of pressure are you running now? Do you have a fuel pressure gauge that you can see while at full throttle? What happens to your pressure as you excellerate?
When was the last time you changed the fuel filter?
Just some thoughts as I read through your post. Need a little more information though.
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fordgasm
CLICK HERE to see my 87 GT