sputters

I have an 1988 YJ 4.2L I6, manual transmission, with a Motorcraft 2100 carb and nutter bypass. I recently swapped the carb from the Carter to the MC 2100 and executed the nutter bypass because the Carter took a crap. It was sputtering and wouldn't start at times. I'm not a mechanical genius but...

The Jeep starts up and idols like a champ! But then lags, sputters then stalls at about 35mph, which might actually be related to hitting a specific RPM. A little background; I recently installed a new Painless Wiring Harness, naturally bypassing the computer. I replaced a NEW...