Ideal Donor Vehicle for 6.2/6.5 Diesel Swap into 72 Truck?

[fishmunger]

Hey guys,

Eventually I want to swap either a 6.2 or 6.5 GM diesel into a 72 4x4 k20 to serve as a tow vehicle. I am not looking for a hot rod (already got one), and I know what to expect power-wise. I just want a classic yet economical truck for towing. Eventually I would also like to get it running on WVO, but I don't know much about this yet (still researching).

I want to start by buying the 'ideal' donor vehicle (in good running condition) and using it for a year or 2 before I begin the swap. I've been doing a lot of searching, but I'm a bit confused as to which year donor vehicle would be the best in terms of economy, reliability, power, and ease of swap.

I have heard that the 1982 6.2NA and the later 6.2 CUCV motors are good candidates because they have strong(er) blocks. But on the downside, they mostly come backed with TH400 trannys (I want an automatic-but I think an overdrive would net me the best economy).

I think sometime in the early 90s they introduced the 6.5 backed by an overdrive automatic (700r4 or 4l80e?), with the option of a turbo a couple years later?

I have also heard, but I forget exactly, that to make the swap easier, the pre '93 or '94? trucks were not computer controlled, whereas after a certain year either the motor or tranny is computer-controlled, which would make a swap into a '72 harder, no?

Sooo, what I'm trying to figure out here is...what year truck should I look for to get the best combination of "old simplicity and ease of conversion" and "modern power and reliability"?

Thanks in advance for the help.