Hey No Rice,
My engine is similar enough to yours, 530", Paxton with currently 8 - 9lbs, 65 lbs injectors, all forged, etc. now at about 850 rwhp in very warm weather.
My current set up is twin Bosch 044's outside of the tank fed by twin "in tank" high volume (Walbro's I think) mounted at the rear corners of the tank. The in tanks feed the central in tank fuel cannister and the Boschs - mounted to a fuel log - pull from it through one -8 line.
One -8 goes up to one side of the fuel rail, with a -8 cross over. At the end of the other fuel rail is a -6 line which then connects to an Aeromotive fuel pressure regulator unit. The -6 returns to the tank from the regulator and empties into the central cannister.
We initially mounted the Bosch pumps in the tunnel and they overheated just like you describe. It took 1 hour in Vegas heat (on my way to the Silver State) and they vapor locked and stopped working. Their temp was about 185 degrees when they failed.
I have relocated the Bosch pumps to the area beneath the trunk, wrapped all of the fuel lines and both fuel pumps with ATP wrap, and shielded the pumps with Inconnel. On a 95 degree day with good humidity, they now run about 120 and are very quiet.
I have learned though trial and error that the first sign of an electric fuel pump struggling is when they get noisy.
I currently have no fuel overheating issues in 100 degree plus weather.
I have had West Coast Viper order a fuel cell to fit my SRT-10 so that I can mount the twin Bosch pumps in the tank (they did the fuel system) and that's what I'll do as soon as it is ready. I'd recommend you do the same, especially living in Vegas.
Heat will kill fuel pumps very quickly where you live, and that's no fun at all.
Good luck,
Dan
PS: Stock pump has a regulator attached to it and no return line.