I had a 59 Wagon with a Six banger in it.
It sounds like yours and mine acted the same way, and it was the Points too far apart.
It would start and run, but it would take forever to get up to speed. If you gave it too much pedal at once it would flatten right out. But if you nursed the pedal it would get up to speed.
It was the points.
97/F-150/4.2L/XLT/Canopy. Old boats and motors too. I like the old Fords but I gotta have the features now that I'm old.