Fuel Blowing Out Carb Vent Tubes Under Heavy Throttle: Expert Opinions Please

Quick update, not spewing anymore. Removed mechanical pump. Drilled a big hole in fuel cap (very suspect as to creating a vacuum and/or pressure in tank but its the same one I've been running from the beginning) drained fuel, dropped tank, inspected filler tube, tank, pickup, hoses, Fram cartridge filter etc. Only running the Carter 4594 electric pump, billet Holley regulater thats rock steady 5.5psi at any rpm. Float levels left as they were, slightly less than 1/2 in sight window. No vent extensions added. Put in 5 gallons of Sunoco 112 for good measure. ******* finally ready to fine tune the *****! Fuel cap not venting or mechanical pump issue I believe, don't care at this point. It ain't doing it anymore. Yeehaw:steering: