Comparing the other truck to yours - how different were they? If the engine came from a 2wd standard cab 1/2 ton with 4.11 gears it is going to feel way different in your truck.
Engine specs? Mileage? Transmission? Gear ratio? There are a ton of variables on why an engine would feel "better" in one chassis vs another.
I'm chasing issues on my TBI 454 right now where I'm way down on power. I think I have traced it to weak fuel pumps based on my fuel trims and the fact that the fuel trims are different for each tank. I did the same thing with chasing parts until I got a cable and software to do some logging and saw that the fuel trims were going crazy at anything over about half throttle. Fuel pumps were "new" as of 3 years ago, but they were crap Spectra quality (installed by previous owner). So installing 1 new Delco pump and will do some logging and see where it goes.
Personally I would not throw any other parts, especially used parts, at it until you get it logging.
Get a cable from here -
http://aldlcable.com/
Comes with a CD that has a couple dozen different scanning/logging programs.