[Walt Fricke]

Bill - I was referring to the model S, not the caliper S. For '76/77 Porsche had only one base model 911. They had the former "S" model CIS cam and the A front caliper, and were the same, US and ROW. The Carrera 3.0 (not sold in the US) and the 3.0 Turbo were the flagship models for those years.

The '74-5 non-S model, with a detuned cam and an M front caliper, always struck me as a silly attempt at market differentiation. But I suppose that is just the automobile business, which probably is proof of the theory that luxury items can have a negative demand curve. Hard to believe the cost of production differential between those two models justified any price difference.

Since the A caliper was for Alfa, where did the M and S designations come from?