This covers all 750 and 800 models up to December 1984, including R80G/S and R80ST. N.B., these heads were not originally fitted with unleaded valve seats, but can be if needed. This price includes supply and fitment of a new exhaust valve guide to minimise the risk of a dropped exhaust valve due to guide wear. We can offer our usual six month warranty if the guide is replaced. Part can be supplied without a new guide fitted for £20 less, but we do not cover damage caused by dropped valves under warranty if you choose this option. Please allow for preparation time if you order one.