Acceleration issues

Ford f150 1987 100k mile v8 5.0l

this is quite the truck ill tell you first off.

when I acceleterate slowly truck will reach up to what the speedometer goes.

but if I acclerate slowly then punch it then the truck will not accelerate faster I have to release the pedal then slowly accelerate will not accelerate fast. When it reaches near 25 mph then I have to accelerate slowly but up to there it is good. NO popping sound or shuddering tho it just refuses to get up and go fast. In park or neutral I can rev up the engine by punching it and it goes up like any other engine just not in gear


New fuel pump. EMS. Timing is good. New plugs and wires. New fuel filter. Recently bypassed the dual fuel tank selector valve and front tank. Put in fuel injector cleaner adn all that other good stuff for cleaning engines.