No, you do not need to do anything with your calipers. I installed a servo on a BN7, a car that was not originally so-equipped. This was sold by British Victoria, a parts supplier now owned by Moss. The instructions were pretty thorough. Among the challenges are mounting the servo at the specified angle on the engine bay side of the passenger side's footwell. You must also run a rubber hose from your intake manifold (a fitting was supplied in the kit) over the top of the valve cover to the servo. My kit had easily bendable piping from the master cylinder to the servo, though in my case I found it necessary to remove the bonnet to route that pipe over to the servo. There is a secondpipe from the brake line junction to the servo. You will need to reform one end of each of the pipes to fit the Healey convention. My servo works very well. I can actually hear it working, which may be comforting to new users.