Mustang68cp

I have a 1990 roller engine in my 1968 mustang..the engine is carburated..i took off my headers and the #4 exhaust port has a built up of what looks like carbon.and the flange has a little oil around it.All the other ports look clean..The #4 plug doesnt have oil on it and it looks like the rest tan in color..I had a bad plug wire about a year ago...would that cause that added carbon in that one port or do i have something else to be worried bout..car ran great b4 i put it away for the winter..any help would be great

mjr46

if the car runs fine and doesn't burn oil , I wouldn't be to worried