How frustrating! I won’t go into my specific problem because it’s a different vehicle, although the same issue. You might consider the previous suggestion of an electric fuel pump. You could plumb it in line before the engine mounted pump, with a toggle in the cab. Fire it up prior to turning the key in order to fill the carb bowls or in the event of vapor lock.

 

The best option I have seen for dealing with this is as resonateur 2nd, auxiliary fuel pump that allows you to prime the bowl.
My 86 460 has the spacer and a quick fuel carb on it.(stock carb did the same) I have insulated my metal line coming from the mech pump to the carb soft line.
Fuel evaporates from the bowl as well and it takes a few pumps and cranks for it to fire after sitting.

 

1” phenolic spacer on my 460 with Holley and Weiand intake, exhaust crossover blocked off, no hot start problems in 100 degree SoCal.

 

Sometime down the road I'll pull the intake and block off the crossovers. I'll also ditch the stock exhaust for either Galaxy 410 high performance manifolds that I picked up at a swap meet or headers. I'm pleasantly surprised with how much power this engine makes despite the terrible stock manifolds.

Eventually I plan to swap the cab and bed over to my '66 F250 frame and shorten this frame to make a short-bed out of it. Golden Star makes all the pieces to build an entire bump side short bed from scratch 1967-1972 Ford Pickup Short Bed Kit Styleside | Classic 2 Current Fabrication (c2cfabrication.com). I will use everything except the bed sides to build an almost entirely new short bed box. While I'm doing that, I'll have easy access to the engine and it will be down for a while anyway, so that's when I'll pull the intake.

That's not a bad idea. That may be a good short-term fix until I'm able to block the exhaust crossovers, which is probably more than a couple of years away as I simply have too many other projects going right now.

The Autolite is such a great little carb! I rebuilt another 4100 carb complete with manual choke conversion and had it dialed-in in just 2 days.

 

Success! It was 75 degrees F today. I drove 12 miles into town and stopped for lunch. When I went back to start my truck, I didn't even have to touch the accelerator pedal, it just fired right up! The Ford insulator gasket works at least as good as the 1" plastic spacer as far as keeping the carb bowl from getting hot. I've also noticed that I can go 2 days without starting and it fires right up.

On another note, I was driving home from the hardware store latter today when suddenly the engine just quit running. I was almost home and managed to coast into a little gas station/convenience store. I opened the hood and saw that the upper radiator hose had blown off the water neck at the manifold. I was able to borrow a screw driver from the store and bought 2 gallons of anti-freeze. I slipped the hose back on and tightened the hose clamps. Both were loose. Apparently, the gush of coolant all over the distributor killed the engine which was great as it didn't even have time to overheat. When these trucks were new gas stations performed routine inspections every time you filled up with gas. I have to remember that it's 50+ year old technology and you have to keep an eye on everything!

I have a correct optional breather with the trumpet snorkel (same as on Galaxies) that I'll use for truck shows, but for normal highway driving I've got a 4" K&N style filter element under the chrome lid now.