SMH, obd2 have the VIN plate on the block if I'm correct, you can call the DMV and have them run the VIN. if the motor was stolen then the numbers would match up to the stolen car. if its not then its clean i suppose. obd0 and obd1 you cant really trace, unless someone is smart and they wrote down everything such as block number and their car was stolen and reported then you could be in some deep shit.

honestly you're better off buying a motor from a wreck car or salvage yard. at least they would have papers of proof you brought it after it went thru insurance. but most gsr or itr are either in someone's garage or being passed around like a whore then its stolen.