smog pump 7801149 vs 7805650

[Frank Bernier]

hi guys

is there any physical difference between
smog pump 7801149 vs 7805650 ??

or is it the same with only different part number ??

thanks
Frank

(my vette is a 69 L-68 )

[Joe L.]

Re: smog pump 7801149 vs 7805650

Frank-----

The numbers that you are referring to are NOT the part numbers for smog pumps. They are the casting number for the cast iron backing plate of certain smog pumps.

All 1969 Corvettes originally used smog pumps with the 7801149 backing plate. I believe that the 7805650 is a much later pump's backing plate, perhaps 1976 or later.

My recollection is that later pumps using the 7805650 backing plate also have a somewhat differently configured aluminum body. However, the later pumps will, FUNCTIONALLY, substitute for the earlier.

[Tom R.]

Re: smog pump 7801149 vs 7805650

Joe:

My research shows the 7805650 backing plate was used in 69 for all applications except L88, L89 and ZL1. The 7801149 was used from 1970-1977, at which time the 7817872 was used from 1978-1980.

[Joe L.]

Re: smog pump 7801149 vs 7805650

Tom-----

I think you better re-check that research. The 7801149 was used from 1968 to about 1975. That's the only backing plate I've ever seen on known-original 68-75 pumps. The original pump on my 1969 has the 7801149. I have NOS 1968 pumps (also used for 1969 L-88/ZL-1), NOS 1969 pumps (real OLD NOS, GM #7803948) and an NOS 1975 pump, GM #7817575. ALL have the 7801149 backing plate.

I'm less sure about the 7805650 backing plate. However, I don't think that it was originally used until well after 1969.

[Mark #28455]

L88 vs L89

In 1969, the L88 used the 1968 style pump with the integral pressure relief valve. The L89 used the "plain Jane" pump just like every other Corvette.
Mark

[Jim T.]

Re: smog pump 7801149 vs 7805650

My original owner 68 has a 7801149 pump that is original to the car.