I'm wondering if anyone else is interested in old Jeep CJs. I recently picked up a 1984 CJ7 that I'm in the process of slowly restoring. I'm not sure if I'm going to stick with the sturdy 258 or swap in a Cummins 4BT.
Keep the original engine, if you can. May add value if you can get it really cleaned up.
But if the engines worn out, maybe. Look at a rebuild cost just to understand options. Last, it's not just the engine you swap out, the whole trans has to swap out also.
The engine runs really well and I pull 21 inches of vacuum at idle.
With the 4BT swap I know it's the engine, trans will be a dodge NV4500, adapter for the Dana, and new front and rear drive shafts. It won't be cheap, but will be unique.
I don't plan in ever seeking this thing. It's ride is horrible, but fun!