Be careful with Adsit. Read their "warranty policy" very closely and you'll see what I mean. Makes you feel all "warm and fuzzy" just reading something like that.
I don't know if Metrics in CA does those or not, but they were once a good source for good rebuilts. The other choice is to buy a used engine or block and have someone local (that you trust)build it. Atlanta Stutgartt is a good source for used stuff in the SE US. Or you could try Aurora Auto in Seattle,WA.