The main difference between the Land Rover and TVR versions lies in the usage of Land Rover 3.9 pistons (usually of the 9.35:1 compression version, some report of low compression (8.13:1) pistons being used in a small number of engines) of which the tops were machined down to match the deck height, thus increasing static compression ratio. Head gaskets were originally copper and slightly thicker than the composite gaskets of later engines. TVR 4.3 engines tended to have elaborately ported cylinder heads with minimized valve guide protrusion into the ports, and Duplex timing chain with timing adjustment by vernier gear were specified although in practice, not all engines received it. Camshafts were usually Kent Cams 214 spec, although 'big valve' versions could have a 224 or even a 234 (race) cam installed.