buying a crate motor from anybody (even ford) is dicey. even crate motors need to be torn down and everything checked. it may be cheaper in the long run,especially if you s/c it, to get the parts to build a short block and have a good machine shop do the work on it. i bought a 390 hp 302 from ford and it ran fine.after a while the motor start going away and i tore it down and sent it off. it was supposed to have been assembled by fords racing dept. and not a normal assembly line.it was about to spin a main bearing so i got lucky. the bearing clearances were way out of spec (why i was losing oil pressure when it warmed up) and ALL the valves on one head werent seated properly.it ended up costing the same money as it would to just buy the parts and have it put together.just my .02. this isnt just a specific incident, i personally know three others who have had the same problems but worse. not from ford but well known companies that specialize in crate engines.