Ok, Im having a bit of a problem, lemme explain. My 82 K5 started (very mildy at first) losing power. I could rev the motor just fine, but when i went to drive it it started cutting out and i barely had my foot on the gas pedal. if i pressed on the pedal more, it would almost die. I could however go about 20 miles an hour without a problem. I am rebuilding the carburator now. (its a quadrajet 4barrel) the engine is a 350. Is the carb the problem or could it be something else? This truck is my BABY!!!!