5.4 / 5.8 GT500 MMR Billet Chain Guides (QTY 4) Precision Constructed of Aerospace Billet Aluminum vs the stock weak casting, eliminates timing variation under high RPM and load. Works with all other factory and aftermarket components. Lifetime warranty against breakage. Red Anodized for corrosion resistance. Laser etched for position/location. No more broken guides on performance applications!! Recommended for all 600+ hp applications Fits all 5.4 / 5.8 blocks (iron and alloy) Made in USA by MMR Includes 4 guides as shown USES Factory WEAR STRIPS (not included) - simply remove from old cast guides and install onto MMR billet guides (easy process) OR select below to add them.