Doable yes. The things going against it are. 1) it shape. The top is wide and square. A lot of tunnel fabrication and on a torsion bar car, cross member fabrication. Its deep. You may find yourself dragging it on the ground. 2) Gears. First isn't synchronized on a 435. Most seem to be granny gear. (6.68). Good launch for the first 30 feet. 3.34, 1.66, 1 might work. It would be better if you have the close ratio version with the 4.56 first. Starting in 1969 dodge started making the np445. Close ratio with synchronized first. But the case is bigger. 3) 68 and older used a much larger truck bellhousing vs the car like 69 and later. 4) It does have a yoke on the rear, but may be able the modify your truck one.
Doable yes. If it's a big block truck and you want to go thought the work. ????. If it's a small block. The pick a part places by me, would sell you a 5sp, clutch and flywheel out of a Dakota for $200.