Made in USA. Melling furnishes timing chain tensioner and guide mounting bolts for certain applications. Timing chain tensioner and guide bolts help secure the tensioners and guide in place ensuring the timing components operate correctly and efficiently. The 5499GMB timing chain guide bolt is an improved design over the original mounting bolt and does not require labor intensive drilling and tapping while reducing installation time by eliminating the cylinder head removal process. Manufactured from the highest quality materials to exacting specifications to ensure worry free operation.