When I hear sourcing a running engine, I'm going to hear it running and check some stuff out before money changes hands. They're out there and so is lots of un-usable stuff. Frozen, overheated, etc. and sometimes it takes a bit of time to find the right one/deal. I tend to chase running ones. Out and sitting on the floor with accessories stripped off is a pass for me. The short story is that magnafluxing a block is subject to human error and much more involved than checking heads for cracked seats. been there with a bunch machine work in a bad block with a 2 year production spread I never could find another one for.
