340 has a hard time starting when hot?
Yeah, if it's turning over fine with the starter, it is not heat soak.
My Sport Satellite had the same exact symptoms & it does have a mini-starter.
The fuel would boil out of the bowl after driving an hour or more & then letting it sit for a car show.
Once I figured it out (those long cranking sessions when trying to leave a car show do attract attention) I started using an old mustard bottle with gas in it to fill up the fuel bowl manually before trying to crank it.
In my case, switching to non-ethanol cleared it up with no other changes.