With 34 psi and 19# injectors, you can only support about 228 hp reliably at 80% duty cycle. Raise your fuel pressure to 49 psi. You should probably get a 155lph fuel pump, too. 24# injectors are the right size for you setup. 30# probably was too big and 19# are too small.
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351W 89 Mustang GT Convertible