Okay, so I was wrong. An adapter is NOT needed to attach a Genesis 1 to part 7503. I could not for the life of me get my hose to thread. I took it to Fastenal to pick up my adapter and they said I didn't need one and screwed the hose right into the manifold. I have no idea why I couldn't do it, but it threaded just fine for them. Weird. Anyway, disregard my previous adapter stuff.
