Are there any mechanics in the house!?!?!?

I'll pm you hogsnatchers.

Here's history. I got this truck in a trade in December of 2011. It wasn't maintained like I would have maintained it, but I got a tune up done and the belt replaced and all that good stuff. Fast forward to August of 2012. Engine wnt bad, ceased up. Took it to the local shop. They swapped my ceased engine for another used engine from a salvage yard. All seemed okay. Fast forward to last month. I was low on gas. Cranked her up to get her to the station to fill up. Started sputtering and hopping like it would if it were running out of fuel. Went next door, got some gas in a can from the neighbor. Added gas. Cranked her back up. Did the SAME thing. Ran two cans of Seafoam through the tank. No better. Had it towed to local shop again. Been there for two weeks now. I gave the most recent part of the story in my first post.

I was referred to a mechanic by a friend who had his engine replaced just a few minutes ago. Said he's not had a single problem with his since. I called the guy, gave him the rundown. He said from what it sounds like is that the used engine they got me was all sludged up from the get go. He said they shoulds recofnized that and sent that engine back to save both parties time miney and headache. He said he will look at it, and give me an honest opinion of what if anything he can do. Going to have it towed to him in the morning. Now I am REALLY frikking nervous....as to me this sounds like this replaced engine may be a sludged up piece of crap! I am so afraid he's gonna tell me it isn't worth fixing! I'm gonna have an ulcer I swear. Anyway, he said it'd take him a acouple hours to go through it and try and get a diagnosis. Charing me $80 for that. *sigh*

Meanwhile, I feel like I've been done wrong by this local shop. Not sure how I feel about that.....