[cdrummer316]

Techs at dealerships nowadays can't diagnois anything without a laptop. Being that your engine is old school they have to guess at what it is. Unless your spark plug wires are 12ft long I doubt that is your problem. But from what I read you saying that it idles fine and revs fine but has no power in gear tells me its a timing issue. I know you checked everything but I can almost guarantee it's a timing issue. I'm a forklift technician and I had an old Yale lift that was doing the same thing your engine is. Even tho this was a 4 cylinder and yours is a v8 the same rules apply. I assumed the timing was fine because it idled and revved and started with no issues. But once in gear it didn't have enough power to move out its own way. Did all the parts swapping just like you, carb, dis, wires, plugs, adjust timing and nothing worked. I knew the cylinder head was off before I worked on it due to a bad head gasket so I checked the timing and found that even though the timing marks lined up the position of the camshaft wasn't right. Moved the cam 180 and put back together. Ran it and it was like I put a new engine. From my experience I don't assume anything. Guess what, someone put your engine together. Don't trust that what they did was right.