alloy S cali. 26k on car stored 25years.
NOS -6 cali. gold turning to silver?

GT-908, aluminum pistons also, now SS.

Thanks Jeff,

This confirms what I've seen when rebuilding the -6 calipers. Every one that has come in the shop is silver yet when they are split, there are traces of yellow in the face of the caliper 1/2's. I am going to try to replicate this with my next batch at the platers.

Also of note; Check out the gold anodized S-Caliper (early 930 caliper) and the either raw alloy or clear anodized racing calipers (908's and others appear this way). I wonder if they're anodized or not

I wouldn't be suprised if they skipped that step for racing equipment.

The 908 caliper looks to be made from a later S-Caliper mold or possibly vise-versa given the 1970 introduction. See the more rounded bull nose on the 930 caliper and the angular cuts on the 908. I have a picture around here somwhere of the later style S-Caliper.

Here's the last set of GT calipers made with the clear finish (silver).

Here's some comparisons of different S-Calipers

Side shot...