This is a new set of 8 bronze valve guides and 8 viton valve stem seals for the Honda CX500/650 and GL500/650 Silver Wing all years. Valve guides are precision machined from C63000 nickel bronze (Ampco 45) for superior wear, friction reduction and heat transfer. Valve seals are metal clad viton construction containing 5% Teflon for reduced friction and wear. Viton is the leading seal material with the greatest resistance to high temperature and chemicals found in fuel and oil. Satisfaction guaranteed or your money back! We offer custom valve train components and full cylinder head services specializing in vintage Japanese road racing. Please contact me if you have any questions. Thanks for looking!