Who would you let rebuild your Holley carb?

Sedanman said

It gets fuel if I pump it but not if I don't. This is a fresh engine I am trying to get fired up to break in the cam and set timing. I have to pump it 3 times and hold the throttle 1/4 way open and with a screwdriver in the butterflies before in order for it to fire. It wants to run but the carb is holding it back. If I hold the throttle at 1/2 or more it backfires. It acts like it's starving for fuel the few times it actually ran for a few minutes.

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This is classic retarded timing.
And if the cam is not broken in, this is not the time to be fussing with timing. By now the cam has thrown most of the break-in lube off. If you have big seat pressure, I would be worried.

Go back and get the timing sorted. She will want as much as possible without starter kickback, perhaps 20 to 25 degrees advance. If you do not know how to do this with the engine not running;just ask.
Then fill the carb with gas. Let it sit for at least 4 hours from the last start attempt, to give the gas that's inside the engine, time to flash and evaporate.

Holleys are very simple to rebuild. If the parts are all OEM for that carb, they are about as simple as it gets. That's one of the reasons they are so popular.