First suspect in backfire on throttle application is the accelerator pump in the carb. Did you rebuild the carb along with the engine rebuild? If not then the pump plunger may have dried out while you had it apart for the engine rebuild.


'38 Chevy 1-1/2 ton
'49 Chevy 1/2 ton
'54 Chevy 6400 2 ton
'55.2 GMC 3/4 ton
'56 GMC 1-ton

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