Carter 750 float level

There is a LOT of BS written about fuel pressure for Carter [ & Edel ] 4 bbl carbs. I have cranked up the pressure to 12 psi as a means of richening the mixture, no problems at all, no flooding.
Your problem could be warped body or airhorn, poor gasket seal, or assuming the f/level is correct [ 1/4 - 3/8"]....& most likely: the steel needle & seats. They just never seal as well as Viton & if they leak, you get flooding. Are you using steel because of alcohol fuel? Somebody must make alcohol compatible Viton needles.