C3 Master Cylinder

[John H.]

72 Manual TM, with power brakes. Build date of car is Feb.22, 1972.
I recently purchased a Master Cylinder from Chicago Corvette. I told them
to stamp it with MK, will this be acceptable for judging?
Page 72 of judging manual states PG stamping for 72's bulit in 71.
Therefore I selected MK for mine....

[Jack H.]

Re: C3 Master Cylinder

The 'stamps' the various JG books speak of that differentiate manual from power brake versions of the master cylinder (DC, PG, Etc.) are NOT rubber ink marks. On the front of the MC there's a flat surface. It was 'milled' with a semi-circular depression roughly the size of one half of a quarter.

In that milled depression, is where the factory stamped the MC's ID code using a steel die (they WACKED 'er in). The original font used for these stampings is quite different from what you see in typical, off-the-shelf, die sets. The characters are quite thin and tall and I don't know of a source unless you supply a rubbing to a stamp mfgr for a 'special' set of dies.

Also, it's pretty well known that not all MC's were stamped with the ID codes. So, absent having a code on what you buy, a correctly configured MC with just the semi-circular mill on the front lip and NO stamp inside should judge just as well...