Hard starting when hot - vapor lock?

[BAsque1]

Wow this is the perfect description of what I am experiencing (still) with my car. It is equiiped with a 427 FE s/o. I have installed the following:
1. Brand new high torque starter
2. 1/2' phenolic spacer (not higher due to hood clearance) the carb is a Holley 770cfm.
3. Removed all-together the useless and faulty fuel pressure regulator, not needed if you run a mechanical pump which delivers 7lbs consistently.
4. New 100 micron in line-filter element.
5. Added water-wetter to the coolant so as to reduce the working temp to 212 degrees.
6. The tank is vented
7. Spark plugs changed
8. Timing is fine.
9. Cooling fans are left on until they turn off themselves via thermostat when engine is turned off.
10 Always use octane booster with every fill up.

However, all this said if I run the car for at least 1 hr and turn it off it will be difficult to start, engine turn fine but it is starved for gas.
Also it is a pain in the rear if I come to a light stop, and must keep the idle above 800rpm to preclude stalling.
I am stomped with this. I am in NY and summers could be 90+ at times. I used to have a similar problem with 123 GT Volvo in Puerto Rico years ago but it was solve by installing a cool can whioch I ran with dry ice and/or isopropyl alcohol.

I don't know what else to do, I have a very professional mechanic who has been analysing this case with me and we are getting very frustrated with this. Has anyone come up with any new thoughts which might work?

My next thing to do is cover the gas lines near the engine and carb with heat insulation material and installing a cool can. Will have to carry an ice cooler in the trunk to replace the ice when melted :-((
Tks guys
Lou