Pretty suddenly my engine started to sputter at high rpms, if you get on it, it smooths out, otherwise it sounds pretty crappy, kind of sounded like fouled plugs and they might have been a touch, but cleaning and new ones didn't fix problem. No hesitation from idle or anything like that, no loss of power. I can't remember exactly now, but it just kind of started doing it when I was still driving it, but parked it for the summer because I was busy. So trying to figure it out. Points should be fine, changed to an older but ok cap and rotor, new spark plugs, changed in line fuel filter. What next? Oh, and also, not sure why, but the rear two spark plugs were discolored on the outside of engine, not sure what could cause that, maybe heat.... 1961 261 engine btw, rebuilt about 2000 miles ago
