Scott89TTA Well-Known Member Joined Jul 12, 2005 Oct 17, 2018 #1 What spark plugs are the guys with highly modified TTA's running...still AC Delco R42LTS, NGK TR5 or NGK TR6?
What spark plugs are the guys with highly modified TTA's running...still AC Delco R42LTS, NGK TR5 or NGK TR6?
J JP112_89 Well-Known Member Joined May 16, 2008 Oct 18, 2018 #2 Autolite 104 or NGK 3177 You should only go one heat range cooler than stock.