I have Been reading on this website(which I think is fantastic!) for a long time now debating the power upgrades of a 5.8 SD in an 89 F250. Massflow is fairly expensive swap, carbed loses starting ease and future tuning, and SD is set at what you have is what you got in terms of pre-programmed fuel adding parameters.
Question, If I build a 5.8 for max low end torque(350h-420t) while still utilizing the factory Sd syetem, could a 7.5 ECU be used to run the 5.8 upgraded with the 24# injectors since what I read is the 19# are limited to around shy of 300? I figure some wiring swaping in the harness etc.
Input from experience or knowledge?
Thank you.

 

19lb injectors will only supply about 300 horsepower, but torque output is independent of that so there is no need to change PCMs or injectors to reach your goal.