My guess would be, based on the information you provided, that your HP will not significantly change, in fact, it may lower because of the force necessary to move the valves.
I do not see a fuel pump upgrade in your list of add ons, nor do I see a properly calibrated MAF sensor for the 24# injectors. If they are something that you just neglected to mention, my apologies.
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351W 89 Mustang GT Convertible