weird smelling smoke!?! please help!

so are you able to run as much advance as you want as long as it doesnt ping? because since i've disconnected my vacuum advance and brought the total down to 42 it doesn't blow nearly as much smoke, and it doesn't stumble at all when i mash the pedal, but the performance isn't as great as it is when the vacuum advance is hooked up with the total being at the 54, but then i have the slight stumble, and the weird smelling smoke.