Swapping to a T-5 is not that difficult with a cable clutch conversion.
I went from a 3 speed stick to T-5 with cable clutch.
The only manual transmission parts that I reused was the clutch pedal.
Most everything else came from a donor 1990-93 Mustang or Capri. Also Mustang Steve for upgrade parts.
Changed to disc brakes, so modified a 1969 disc brake pedal for manual transmission. Replaced old worn pedal hanger with used from automatic. Added a better bushing kit, could have used roller bushings (even better).