Mar 29, 2009 #1 J jhanson1750 just a 10th quicker Joined Apr 24, 2005 Messages 1,114 Do you run them or not. Jon Hanson
Mar 29, 2009 #2 C charlief1 RIP Charlie! Joined Sep 20, 2007 Messages 23,936 If the heads are stock no, if you've modified the heads and are running different valves yes.