6.2 Diesel in a 69 3/4 ton 4x4

[brandoncpm]

Hi fellas, about to begin on a project to say the least. I have a 69 chevy 3/4 ton 4x4. It currently has a 350 and a 4spd manual. I just picked up an 83 chevy 3/4 ton 4x4 with a 6.2 diesel and a 4spd auto in it for a donor truck. The goal here is to swap the powertrain out of the 83 into the 69. From what I can tell so far it appears that the 6.2 should fit nicely in the 69. My goal is to have a daily driver that not only looks awesome but gets in the 20's for mileage. I should have most of the parts I need already in the 83. My question is, will the 6.2 bolt up to the 4spd manual currently in the 69? If so, am I wasting my time and effort swapping the auto and transfer case as well? If the 6.2 will bolt right up to the 4spd manual, it would obviously be a lot easier than swapping everything over, however, I would really like the automatic just for space in the middle seat as well as in town driving convenience. My biggest drawback about keeping the 4spd manual is that it is geared really low and at 60mph I am currently turning 2500+rpms. I suppose I could swap the gears out but I would rather have the automatic with overdrive for sure. This will be my first motor swap project so I know there will be a lot of headaches and frustrations but I am very mechanically inclined and a good fabricator so the diesel end of things may be new but I can figure it out.....with enough help from some of the more experienced guys on the board...Any help or recommendations will be greatly appreciated. Thanks in advance.

Brandon