I got my stuff off a 1979 Ramcharger, However many people I have talked to say that dodge changed the set up in 1979. ( from reverse to standard rotation gear box) I don't know if the Truck I got my parts from was a "mutt truck" by a Previous owner, or if dodge threw some '79s together with left over parts from '78.
My advice to you would be to look for parts from a '76, '77 or '78. 1/2 or 3/4 ton. full time 4WD,
I do not know if parts from a 2wd would work.
(gear box, Pitman arm and drag link )
I do not know if parts from a part time 4wd would work
( gear box, pitman arm and drag link )
The biggest thing to look for it to see if the gear box mounts directly to the frame,or sits on a bracket, like your manual gear box does now.
all P/S pumps , brackets and hoses should be the same if coming from another 318
I was able to use the existing crankshaft pulley that came on the truck so you shouldn't need one of those...