First off, you double posted, so I removed one of them. Not a problem...it happens all the time. On your stalling when she gets hot, it sounds like a classic case of vapor lock. That's when the gas in the line or carb gets so hot that it turns into vapor so won't burn. Since 1988 was the first year for Ford to use fuel injection instead of a carburetor, I don't know what to tell you about keeping heat away from the EFI, but double check your fuel lines to make sure they are not near the exhaust manifolds. The guys with the 5.0's will be along here sooner or later so hang tight.