My 54 A10 has just past 1,000 on a rebuilt engine from a reputable builder. Runs great.
One oddity I noticed was that one exhaust pipe was more discolored than the other from heat. Applying my magic ray gun laser thermometer, I found that the left pipe was about 210 F and the right about 170F with the engine warmed up for about 5 minutes or so.
Anyone think of a reason for this? Is it something to be concerned about? Timing is right and plug color is actually darker than I would like, making me think its running a bit rich, not lean.
It's most likely the bias on the carb, I know at one time you could get a bias washer to fit between manifold & carb, if your carb has a 'O' ring try loosening one side & tightening up the other just to slew it round slightly..