One other thing I learned that I suspected was correct. The main body OD o-ring will NEVER see gas unless the 4-hole gasket is leaking. If the 4-hole gasket is holding no gas ever enters the valve housing. The o-ring is basically a fail-safe device to prevent gas from pouring out of the valve and onto the engine should the gasket spring a leak.***
Interesting. Never thought of it that way but it seems feasible.
I have a couple spare units so I will be putting a kit in one of them soon.
For the space left because the gasket is smaller, couldn't you simply put a o-ring in there to fill the gap? Looks like one the same size as the one supplied would fit .