Acceleration problem

[LeesTruk]

Ok, I brought my 5.3L to life, and after taking care of some engine swap teething problems (leaking ATF line, and a faulty O2 sensor), the truck will idle cleanly and will easily rev in park/neutral. The problem occurs when trying to drive the truck. While trying to accelerate, it's like someone turns off the engine until I take my foot off the gas pedal, then it comes back to life. Does this sound like a TAC situation? Supposedly the TAC/PCM are from the same vehicle as the engine, as well as the pedal. The only code I have is a P0654 RPM code, but that's most likely my tach hook-up (bad ground), I've seen similar concerns here, but no reply on what cured the problems. Any guidance would be greatly appreciated. Thanks

Lee