auto into and manual??
With a 351, the Mazda tranny can work if you are easy on it, but supposedly there is the rare ZF5 in F150s of that time.
Basically, pop out the shifter plate, shove in tranny, swap in manual tranny driveshaft (probably different length than the slushie version), swap in clutch pedal assembly and hydraulics...
Basically, borrow a donor manual tranny truck and take notes.


