Based on the 'what would you do post,' isn't it obvious that you will have just a good a chance, if not better, if you simply use a large, engine reman vendor in your area?
(Over $5k, and the results are: a knocking engine and busted tranny. I can only imagine what I could do to my car for $5k! One step further, imagine what type of car $5k will buy you! I see plenty of turn key cars in that price range that are very-bery nice cars that need nothing.)
I used one, Sun Engines, Regal Row (or Roundtable), Dallas, TX in 1987. 300k miles and, 3 th350's later, it's still running strong, and I wouldn't hesitate driving it across the country.
