Carb problems?

hey, need help. I have edlebrock dual quads on my 73 360 Duster. 1404 and 1406, 500 and 600 cfm the car always ran great until today. It spit and sputtered and backfired very loud. It died on me 6 times in 2 miles. It will start but won't stay running. I had to have it towed to home. Stuck float? No leaks of fuel, just won't stay running. Any experts out there.