Intake Gasket advice

It would make sense that fuel would deteriorate them. The OE system is dry...

That's only sort of true. The injector sits right at the port opening, so some fuel is likely to get on the seals. Not as bad as a full wet carb intake I'll agree, but it's not perfectly dry. I can't imagine they would put a non-fuel resistant material in a place so close to fuel, but I guess stranger things have happened. The 6.1 intake is metal right? I was thinking maybe the factory seals just don't like the metal aftermarket intakes, but if the 6.1 is metal that theory goes out the window.