I need an education on identifying correct casting and date codes for master cylinders and power boosters. I have a 68 with power drum brakes and the master is oval with bleeders a date code of 38 on fender side and a casting # I have yet to clean well enough to i.d. on the engine compartment side. The booster does not have Delco imprinted and has 123 on small tab at top. I have seen many with the Delco imprint but If I recall they were disk brake equiped.
Pat

I think that the 123 was a Julian date. The master cylinder is also Julian dated, same for the power steering box.

That was my conclusion as well. I still am confused if the delco stamping was on factory boosters? I see the aftermarket offers a stamped version and plain?