Product Details All valve guides are made of Ampco-45, a high-performance compound with 80% copper content to provide great heat conductivity and 5% nickel content for wear resistance Made in the U.S.A. Product Videos Custom Field Product Reviews Write a Review Write a Review × Kibblewhite Kibblewhite #60-60300 - Valve Guide Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *