All parts listed are suitable for saloon, sport & 4x4 applications unless otherwise stated.
Various different valves have been used since the Rover V8's introduction; most having the standard 'Rover SD1' head diameter: inlet - 40mm, exhaust - 34mm. However, early engines (pre 1976) were fitted with smaller diameter valves - 38mm inlet, 33mm exhaust - which are less efficient. In order to benefit from the larger valve sizes, it would be more practical to fit a pair of later cylinder heads than to attempt to fit the larger valves to early heads.
Vitesse specification valves are of standard SD1 head diameter, with waisted stems just behind the valve head.
The largest valves that can be fitted to the existing valve seats (later heads only), without the need for extensive machining, are our Big Valves (Inlet - 41.4 mm, exhaust - 35.5 mm, with waisted stems). These valves are particularly suited to large capacity engines. (Note: some machining is required to the valve guide and seat).
Finally, the latest factory valves, as fitted to 3.9 & 4.2 engines since 1993, as well as the Series 2 Range Rover (4.0 & 4.6 engines), feature the same head diameter as SD1-type valves.
Note: All parts supplied are suitable for unleaded applications.