I have a 300 6, 1989 F150. What transmissions will bolt up to that engine from that era.

 

Auto:
C6
AOD

You could retro an older C4 if you had to.

Manual:
Mazda
ZF
(both are integral bell, hydraulic clutch with concentric throwout cylinder. The Mazda was put in F150s, the ZF in heavier trucks)

You can retro older 4 speed manuals and other non-integral bell transmissions by getting an older bell, some of which were set up for hydraulic clutch. ('84 & up IIRC)

What do you have now?

 

the mazda 5 spd