I have purchased a couple of the GM replacement engines over the years. Both engines have given me great service and reliability and I would do it again. For the money it is easy to do. Look up Scoggin-Dickey's website and see what they haveon hand, to get prices and ideas. The last engine I purchased < i changed the cam in it prior to installation. I know that did me no warranty favors, but that is the trust that I had in what the product was. That engine is still performing good in my Son's truck.
http://www.sdpc2000.com/