disclaimer: i'm old, i ramble on, this should probably be printed and taken to the crapper,
well i hope this is where i go for help. in 1976 my step-dad bought a new 620 and though the years it ended up being the beater truck around the farm. i have it now, drove it for years, it has about 150 K on it, but it only sat 2 people, so it ended up out back (i now live in the desert). the kids are grown, seating 2 is fine now. and thru penny saver and a wild hair (that's what my wife says i get) i bought a 1980 720 fwd power train and chasis for it (it had a bad engine). it was amazing how everything fit, I think it was the only year that the 720 had a L20 engine. when i had a problem fitting the fan shroud on the radiator, there was a engine mount that moved things in the right spot. the engine oil pan hit the front diff,swap the pan from the 720 engine (and the dip stick and oil pick up). the cab and bed mounts lined up. the only cutting was on the fuel tank mount (the 720 has the tank mounted on the frame instead of the bed) and the cab where the steering gear/box is mounted (but even that has a reinforcing stamp. it seems like Datsun had this option somewhere in the world or at least thought about it).
but it's hard to find parts, i'm seeing parts on E-bay, are they any good? i need a new windshield seal, the dash is pretty cracked up. need to change to bucket seats for the transfer case shifter (my son has a 90's subaru i might talk him out of). any help finding parts of decent quality, thanks