47 Flathead carburater woes

[modelamodela]

Have a 47 flathead running on a Holley 2100 with a Purolater electric fuel pump and a flow meter set at 2.5. Starts up easily, runs and drives for 10 minutes, then looses power and stops. With effort, it will restart but stops again. After waiting an hour or so, will start up fine, run another 10 minutes or so, then stops again. Feels like fuel starvation, but hey, what do I know !!! What is the problem??