One problem you may encounter is that the 230/250 6 cylinder stick shift models of that era used a very small radiator. The 292 6 cyl and V-8 trucks not only came with a larger radiator but a different core support. That could become an issue considering you are also switching to an auto trans. Also, a shroud will likely be needed because of the distance between the fan and radiator.
Fred
I own a 230ci and a 250ci. The 230ci had a tall narrow radiator that sat on saddles mounted on the lower flange of the radiator support cross member. I swapped out the 230ci for a 250ci. My donor truck had a V8 style radiator which is wider but not as tall.
The radiator core support is identical for both, so I must disagree with Fred. The 230ci radiator had a special shroud that channeled air to the narrow radiator and thus prevented air from flowing around it. The wider radiator didn't use that shape shroud.
If you go with a SBC, then the V8 shroud you would likely need is sold by many of the vendors and makes the pull of the fan more effective since the V8 SBC sits back from the radiator quite a bit.
I can post photos if there is any interest in seeing the 2 different styles of radiators. The 2 different ones I have are both original Harrison radiators.
