Bought a Ride recently with a mid ‘60’s BB Mopar. Supposedly rebuilt many years ago then owner died shortly after & kids left sit in garage. I drained all fluids pulled plugs sprayed lub in cylinders let marinate put new coolant, new fuel line, temporary gas container, a fairly fresh carb, fresh plugs, wires & oil. Spun the engine up a few time w ignition off then turned on & it fired up. It had good oil pressure so I let it run for a 1/2 hour with no smoke, stayed within heat range. I noticed intermittent roughness coming from left bank only, had good spark to all plugs. Figured it was probably sticky lifters. I put typical super lub additives in oil to see if it would help & have been driving! Runs great for a bit, then the roughness, then good, back & forth. Sometime when rough stalls @ idle. Roughness always only from left bank. Any suggestions to free sticky lifters w some kind of additive? Was thinking maybe Liquid Molly lifter additive? Slick 59 & Marvel Mystic didn’t help.