I installed a 350 small block in my 82 D 50 4x4. I used a Muncie SM420 tranny and an NP231 transfer case. I used the Ford F150 high pinion Dana 44 front axle.
I kept the radiator in the same place as the 4 cylinder one. The biggest problem was the bellhousing.
It is an enourmous amount of work but is well worth it. My truck Kicks Ass now.
[Linked Image]
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