Hard starting

[Bills64]

I have a 17057274 carb that when driven (fully heated) and I go to start it after sitting a couple of hours it's hard to start. I believe it's flooded because I have to keep the pedal to the metal for it to start. I pressure tested the plugs on the bottom side and they didn't appear to be leaking, just wondering what other causes for this.
Thanks,

[quadrajam]

If you have a steel fuel line to the carburetor and a mechanical pump,sometimes
engine heat can cause the fuel to boil in the line and overcome the needle/seat.
Make sure its not bolted to somthing hot. If you have a return line on the pump
then your probably OK. I had to insulate my lines.

Is the choke coming back on?

Do you have at least a 1/4 inch gasket under the carb?

What may help is to run a 3/8 hose from the fuel vapor nipple on the front of
the carb down to the area where the vapor canister used to be. just open ended.
Easy enough to try. Helped mine.

[von]

Many aftermarket stock replacement mechanical fuel pumps have too much pressure for a Q jet to handle, especially after a "heat soak when pressure builds even higher in the line between pump and carb. I had that problem and an AC Delco pump from a Chevelle parts vendor cured it.

[Jeff K]

1/4" steel tubing return lines are pretty much manditory with todays heat sensitive ethanol fuel. Get a fuel filter for a 1963-64 Pontiac G.P. or Bonneville 389 with A.C. it will have the return line port and send unfiltered gas back to the tank.