Ford Cortina Mk3, Mk4, Mk5 1.6,2.0 Pinto Piper Cams 33mm Extended Ball Studs BSTUD33. This is a Brand New set of Piper Cams BSTUD33 33mm Extended Ball Studs to fit. Brand New set of Genuine Piper Cams Ball Studs. If you have any questions please contact me and I'll do my best to help you as soon as possible.