DIAPHRAGM SPRING - Pre-Verto types
PRESSURE PLATE- Pre-Verto & Verto types
Pressure plate - Pre-Verto types.
22A598 - Number cast in. Standard-grade cast iron 22G270 - Number cast in. High-grade cast SG iron as fitted to Coopers and Cooper Ss Quinton Hazel - Triangular in shape, but only standard-grade cast iron. C-AHT230 - Mini Spares high-grade SG cast iron, but cast pre-lightened. Farndon Engineering - Machined from steel billet.
The first two can be lightened, see accompanying diagram. Limit removal of metal on the rear face to 0.120" to be safe, 0.150" if you're feeling brave/lucky.
Verto to Pre Verto,Clutch swap
Historical Article - Nov 1991 - Gain Acceleration - Fit a Flywheel