I really appreciate all the good replies and will try to answer the questions asked:

John Evans-Yes I have the fuel return line, the optional kit from Kitfox installed exactly as they say. It does tee off from between the fuel pump and the carbs thru an orificed (factory supplied) fitting. It goes directly to the side of the header tank thru a check valve. It should have nothing to do with the vent line from the header tank to the right wing tank.

Papua Pilot & others-Yes I will admit I quite often fly with 1/2 ball to the right because I need to add a little more right rudder trim tab. If I don't keep a slight right rudder pedal pressure it flies 1/2 ball to the right. Maybe you guys are on to something here!

DessertFox4-Yes I have used Hysol to close those 4 little holes in each cap based on your previous post. However I do agree that it probably is unnecessary.

JPitkin-It is possible I may be flying with the right wing low at times due to the unbalance when the right wing has more fuel in it than the left, which is quite a bit of the time. I will consciously try to avoid this and see if it helps.
I also noticed that my fuel cap vent tubes are close but not perfectly aligned with each other; will fix that.

I will report back after acting on these suggestions. Meanwhile any other advice or comments are welcome.