Recommended for use with 2011 Mustang GT 5.0L when running with a supercharegr. One heat range colder than the stock 2011 Mustang GT 5.0L 4V engine spark plugs 0.035 plug gap for supercharged applications recommended. Sold in sets of 8 M12405M50$109.95 www.realspeedauto.com Ph.631-563-7325 All parts listed are for the Ford Mustang unless otherwise noted. Copyright 2018 Realspeed Automotive Inc. All rights reserved.