Hope you have deep pockets. You are going to need all of these parts to do it right, or you could spend about 1/4 as much and rebuild the TH350, or spend 4500 bucks for a tremec 5-speed conversion. go to www.keislerauto.com

Rebuilt Muncie 4spd (M20 or M21)... has to be small output shaft tail ext to work w/ correct fitting shifter.
-Correct 68-69 4 speed shifter
-console (if desired)
-Quality clutch & pressure plate (Hays, Center-force, etc)
-10.5 or 11" flywheel (uncracked)
-early F-body m/t pedals, throwout bearing arm
-Z-bar (clutch linkage)w/ clutch pedal rod
-'69 back drive linkage

now parts are getting cheap...
-bellhousing
-repop or good used shifter purch
-throwout bearing
-different backup light swith for '69 column
-two ball studs & subframe mtg bracket
-rubber shifter boot
-outboard column sealing plate & rubber boot
-return spring
-Flywheel to crank bolts
-pressure plate to flywheel bolts