You are associating one problem with another, the running rich thing, just lean it out a little, just dont go more then like four or five percent across the board, even less past 7K, until you can get to a dyno assuming your pretty close to stock, as far as your valves, running rich is safer for you motor then running lean, your valves shouldn't be affected at all any way, and what does this all have to do with a electrical load sensor????

Aj