Tuning suggestions.

[greasyspider]

  I have a 440 in my 71 charger that is bored 40 over.  I have no idea what it has for a cam but it I'm assuming it isn't stock.  The carb is the original 4968s carter AVS (freshly remanufactured by the carb doctor).  When I tuned the car to factory specs it overheats like crazy.  I advanced the timing about 10 degrees, and now the temp is normal, but it hesitates when I give it gas. But only when under load.  It sometimes will stall unless I let off.  My first inclination is that it is starving for gas.  It seems to get worse going uphill, which makes me think float level, but I just set that and it ran fine (aside from overheating) before adjusting the timing. Mixture is about 3 turns out on both sides.  My other thought is that I've got an advance issue, but I have no idea how to set the advance.   The set screw was wound all the way in, I counted 12 turns until backed all the way out and split the difference, (6 turns from tight either way) but still no change. Any ideas?

[greasyspider]

I should add that what prompted me to adjust the floats was fuel leaking through the throttle shaft.   The passenger side floats was lower, I adjusted them to 7/32 and it got a little better.  I think the problem was more due to heat however.