1973 Corvette A.I.R. Emission System Pump (Model Type) ?

[George H.]

^rd

[Joe L.]

Re: 1973 Corvette A.I.R. Emission System Pump (Model Type) ?

The original factory A.I.R. system on my 1973, LS4 with AC, has a pump with an iron backplate casting # 7801149. It is date coded 13032S (05/10/73). What is the significance of the “S”? Our 3^rd edition tech manual only calls the last alpha stamping as a model type? The engine build date was 619 (1703 / June 19). I assume the “S” is the specific factory model type for a 1973 LS4 engine with the option of AC (C60). Am I correct?

George------

All Corvette AIR pumps from 1969 through at least 1975 were "S" model pumps except 1969 with L-88/ZL-1.

[Richard K.]

Re: 1973 Corvette A.I.R. Emission System Pump (Model Type) ?

Joe Lucia,
What was the difference with the '69 L-88/ZL-1 ?
Thanks

[Joe L.]

Re: 1973 Corvette A.I.R. Emission System Pump (Model Type) ?

Joe Lucia,
What was the difference with the '69 L-88/ZL-1 ?
Thanks

Richard------


1969 L-88/ZL-1 were equipped with a "Y" model pump. This pump is of similar configuration to the aforementioned "S" model pump except it had an external pressure relief valve. The "Y" model pump was also used on all 1968 Corvettes as well as most other 1968 GM cars equipped with AIR.

Below are some photos of an NOS example of the all 1968 and 1969 L-88/ZL-1 AIR pump. This one was assembled on the 256th day of 1968 and packed in a box dated 9/21/68. [not for sale]

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