Yes, going to 8s was recommended to me by Dunfords when I had my '04 & it was fouling plugs. Also, make sure your MPEM has the latest update for the fuel mapping.
"A bad day on the trails, beats a good day at work!" Revrnd
"We're on a mission for God" Jake & Elwood Blue
"Remember, if you haven't got anything nice to say, say it often." Ed the Sock
2004 Chev K2500HD
1986 Chev Monte Carlo SS