Just a few degrees late on ignition timing can cause the hesitation/bog/backfire symptom pretty often. Try turning the distributor housing a little bit counterclockwise (opposite the rotation of the rotor). I've solved similar problems by simply advancing the initial timing 2 or 3 degrees.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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