1800cc cars must use a 47mm throttle restrictor. 1800cc cars must use a 45mm throttle restrictor. B. Engine 1. C. Cooling System 1. Any aftermarket metal-type radiator may be used as long as it mounts to stock location.
Thermostats are free.
D. Intake System 1. 1600cc may use a cone-type air filter. 1800cc must use a stock air box. Filter is free. E. Fuel System Unleaded fuel filler trap door and restrictor plate in filler neck may be removed.