I have a 1973 bus with no servo, but im wanting to add one to it as it now has an impreza engine, my question is can i use a subaru servo? or should i buy a proper vw one? what else do i need to buy? i have bought the brake lines and master cylinder that accomodate the servo the beam i havent decided on yet i am undecided whether or not to buy a new beam or weld brackets on to hold the servo any help welcome!! Luke