You said Tom Tellford couldnt get the scanner to work, I would guess the reason behind this was he didnt know the VIN of the rig the motor came from, this is a important piece of information, I spent most of an afternoon trying differnt options on my brick scanner to gain acess to the computer. Mine finaly came down to it was from a 94 stick shift Astro van, that took awhile to figure out, who would have thought they even made stick Astro vans.
Not trying to make you mad here, but you kinda seem to be that type of guy that makes my life rough at the shop. Changing this, and that, throwing parts at a problem you dont understand, while usualy adding who knows how many new problems before you give up and finaly send it to a shop where you probably would have spent like $60 for an hour of diagnostic, and at least be headed in the right direction.
Sounds like you should ask around & find a desent shop in your area, oh and imo do not try a new wireing harness or put a cummy carb on it my .02
Good luck.:beer: