Sorry to be the one to give you the bad news, but the Salvage Yard will at best give you $250.00 for your Jimmy. You may be better off installing an other engine from a Salvage Yard to get yours running for $800.00 and keeping it or selling it for $1,500 if the Jimmy is in great shape and running great.
How do you know you need a new engine?? Send me a PM.