carb problem?

it pops regardless of where the timing is set. it ran perfect before it went to the body shop. no lifter noise either, and the vacuum advance is plugged. I didn't adjust the float levels, just took it off...and blew it out with compressed air, thinking that there may have been some dirt in it.
Could it be the plunger not pushing enough fuel through under quick acceleration? it only pops when it's given that quick shot of gas.