[Walt Fricke]

You can tell from John's chart. For '74-5 Porsche offered a lower powered 911 (listed as "911) while the more powerful (but same displacement but listed as 911S) was a bit more expensive. The non-S had smaller ports and a less aggressive camshaft. Silly attempt at market differentiation, as the cost differentials to Porsche for the motor components, at least, had to be 0 marks. The chart lists both.