S Alloy Caliper's

[Dean DS]

I am new to 911's so excuse the question. Are "S" alloy calipers the same for front and rear? If not, what is the difference?

My other question is are all S alloy calipers the same from one year to another eg '67-'73.

Dean

[TRE Cup]

S alloy calipers were fitted by Porsche, from 1969 thru 1977. They were used on the 911s , the early Turbo (1975-1977) , and as an ordered factory option on the T's and E's. Some E's were standard fitted . They were not dealer installed as the struts would have had to be changed to fit them.
There were two versions. The differences were slight and in the castings around the bleeder screws. I forget when they changed the casting, but the early version has a slight shroud around the bleeders. Later ones did not (made it easier to bleed with a standard wrench instead of a socket)
S alloy, A (cast iron- same pad profile, but thinner cross section) calipers were only fitted to the front suspension. Never on the rear, where the M sized caliper, were installed