TR5, TR250 and TR6 (inlet valve) ? TR2 to TR4A (inlet valve) and TR4 from engine no. CT21471 plus all TR4A (exhaust valve) ? Spitfire Mk3, Mk4 and 1500 (inlet valve and exhaust valve) ? GT6 (inlet valve and exhaust valve) ? 2000, 2.5PI and 2500 Saloon (inlet valve)
TR5, TR250 and TR6 (inlet valve) ? TR2 to TR4A (inlet valve) and TR4 from engine no. CT21471 plus all TR4A (exhaust valve) ? Spitfire Mk3, Mk4 and 1500 (inlet valve and exhaust valve) ? GT6 (inlet valve and exhaust valve) ? 2000, 2.5PI and 2500 Saloon (inlet valve)
TR6 from September 1972 - Carburettor models from engine no. CF1, P.I. models from engine no. CR1 ? Spitfire from January 1972 - Mk4 from engine no. FH25001 and FK25001 plus all 1500 models
TR250 (1967-68), TR6 Carburettor models to chassis no. CC85737 (1968-72) and TR6 P.I. models from chassis no. CP75001 to CP77718 (1971-72) ? Spitfire Mk3 and early Mk4 to engine no. FH25000 and FK25000 (1970-72)