309 power disc master cylinder

[usa1ti]

is the 5468309 power disc master cylinder 69 only? I have one for my 05A car within 10 Julian days of the brake booster. Booster is 127 master cylinder is 117. 117 is a Sunday??? seems odd to me.

[rszmjt]

117 day is Sunday April 27. The casting foundarys might have run 7 day weeks. Kurt May know , maybe he will chime in.

Does yours have the US stamp?

[usa1ti]

Yes has the US stamp on front pad. It’s a GM original to replace the aftermarket one on the car now. All seems to check out as original and 10 days before my booster which lines up with 05A car. Unless the 309 was used in 68 or 70 they would have had to be working 7 days to get that Julian. I’ve just never noticed a Sunday Julian before.

[69Z28-RS]

Isn't it also possible that it was made on the 117th day of '68 (even if intended for '69 models?)..