Smog pump date code

[ALLZS]

I have a pump with 13881Z stamped on it is this a 68 pump also I have seen with a S at the end of the date code but not a Z

[X66 714]

I found this on CRG....Joe

The last digit is the configuration code of the pump. The 67 pumps are coded A and C. (67 Corvette pumps are coded P and are unique to that application.) The 68 pumps with a pressure relief valve installed in the pump were coded Y. Non-pressure relief valve 68 pumps were coded Z. 69 and later pumps (without a pressure relief valve) were coded S.

[ALLZS]

ok thanks so it looks like a 68 pump without the reliel valve, did a certain model use the with or with out on the valve

[X66 714]

This is also from CRG....Joe

The 68 pumps used on Z28's and big blocks had a pressure relief valve installed on the side of the pump. The Z28 relief valve has a green plastic plug and the 396 relief valve has a black plastic plug The 68 pumps for L6, 327, and 350 engines and all 69-and-later pumps did not have the pressure relief valve on the pump; it was incorporated into the diverter valve.

[ALLZS]

Good info thanks