Alright so i finally finished replacing the head gasket and the valve stem seals.
Seems the car is still getting some oil or gas (seems to have a gas smell but i'm no expert) onto the 4cyl spark plug and a little on 3cyl. I smell the same smell when i open the oil filler cap that is on the spark plug.
Could it be
1. the fuel pump diaphram is bad, gas mixing with the oil, thinning out the oil and somehow making its way into the cylinders?
2. somehow its not burning up fuel all the way and its just gas on the spark plug, because it is still backfiring like crazy and i'm positive it is trimmed correctly.
and if any of those things were the case why is it really only affecting cyl4?