If it matters, I feed my 499" with a Dominator with a mech fuel pump.

Occasionally at the track on a warm evening, I would get a little starvation at the big end. So I put a Holley black above the rear axle on a manual switch under the dash.

That helped, but I still got the occasional starve on the big end. Long story short, after a lot of flow testing into a gallon milk jug, I ended up with a larger fuel line from the tank to the engine, reamed out the smallest ID fittings and fitted a micro switch on the carb's secondaries to actuate the electric pump.

That's been several years ago. Now, I do not have any starvation problems, do not have to listen to an electric pump running and have a built-in buck-up system.