340 has a hard time starting when hot?

92 starter on my 367
As to the fuel, I run 87E10 full time with zero problems.
And the only band-aid is a hole in the hood feeding fresh cold air to the 750DP, on the AG intake.
However, my combo did not have a serious problem before the modification.
The carb itself is still sitting in the hot as Hades underhood environment.
I run Aluminum heads and a minimum coolant temp of 205*F and don't forget the un-wrapped TTI headers. So it gets really really hot under there.

Click-Vroom every time.
But she's a more or less DD so the fuel is always fresh.
Take a fuel sample; it needs to be from clear like water to yellowish. When it gets to the Orange stage, yur gonna have trouble.I Run fuel-stabilizer in all my Lawn N Garden stuff, that sometimes sits for weeks before the next usage.

I run a mechanical pump and 3/8 line, no choke. The EFI filter is back at the tank, with a one-piece home-fabbed line from pump to carb, no return. No carb spacer, no reflective wraps, but I do have an RPM AirGap. Click-Vroom, every time.

I live between the 49th and 50th parallels at 930 ft elevation. The hottest summer day is not likely to exceed 100*F but on occasion has. In summer it hovers around 85/95; a paradise it is;for about 8 weeks,lol.
If you suspect the carb, and it's a Holley; Drain and capture the fuel from the front bowl;it should measure about 50cc of clear fuel.

The lightest elements of gasoline begin to boil off at 100*F, and the heaviest not until 400*F. Ethanol's boiling point is listed as 173*F.