Ron, you bring up some good points.
Point #1.... Buy a donor and resell the leftovers.
This approach works fine if you have the space and are not at the mercy of a hostile HOA.
Point #2.... Buy from a recycler.
Do your homework on the particular recycler. Make sure you get all the associated parts.
Point #3.... New or build harness.
Depends on you or your buddies skills. Of course modifying the existing harness would be the cheapest.
Point #4.... Which engine is best.
Go with what you know. Venture into the unknown if you have knowledgeable friends who are willing to get their hands dirty.
I did the 350/700R4 on my ‘62 C-10. Had the engine built cost $3500. Transmission was a recycle special and as installed cost $200. New driveshaft was $150 with new ujoints. P/S and P/B conversion was another $900. New 4 row aluminum radiator was $220 w/new hoses. Total expense when finished was a bit over $6000. I did everything except build the engine and driveshaft. Took a year to complete.
