Originally Posted by
RogerH
That may be the case for a post December 1977 car but the T&C rules are different for pre 31 December 1977 cars.
For these pre cars, brakes are "free" subject to disc and drum friction surfaces being ferrous. "Free" means that the original part may be replaced with a newer part as long as the new part provides no additional function relative to the original part and must be from the same era and was available or used on that make and model in period. "Era" means the period when a particular vehicle model and its components were actively used in motor sport competition.
This could be interpreted to mean that an original 4 pot calliper could be changed to a Wilwood 4 pot of similar dimensions if it could be proved that the Wilwood (or the form of calliper on which the Wilwood was based?) was available to be used in the period (era) related to the subject car.