Mar 19, 2008 #1 R rickrat Full Access Member Joined Feb 25, 2008 Posts 50 Reaction score 0 Location Coeburn, Va. What size pipe did the factory use on stock 6.9 engines?
Mar 19, 2008 #2 FordGuy100 Registered User Joined Apr 1, 2006 Posts 8,749 Reaction score 282 Location Silverton, OR I think it was something like 2.5" OD (outside diameter)