Reviewed By Damon N (Elkridge, MD) Reviewed for a 1998 Ford Mustang —4/18/2012 9:22 PM
Had these installed, when the stock exhaust manifolds developed a crack. Turned out to be 300 dollars cheaper than going with the stock GM manifolds. Very surprised in the performance increase from the stock 6.0 Liter engine. Seems to have quicker throttle response, and a noticeable difference in low end torque. I also noticed at highway speeds (approx. 70 mph), it is running about 500 rpm lower than it used to, to maintain the same speed. I am sure there is a small gain in gas mileage, but I probably wont see it, since I seem to want to put the foot down harder now.