I am searching for an AIR (smog) pump for my early model '68 L36. What is the correct GM part # for this pump? I believe the pumps have a white fan (???) Engine build date of Sept. 21/67. What would be an acceptable julian date code for the pump. Also, what is the correct GM part number for the pump bracket (also missing in action)? Thanks in advance for the info/help.
-
-
Re: *** '68 AIR Pump Question ***
Blair------
The part number was GM #7801512 but that number will be found nowhere on a pump unit. The 1968 pump was somewhat unique in that it was the 68+ style pump with an external relief valve. The only other 1968+ application that used this configuration was 1969 L-88 and ZL-1. The 66-67 AIR pumps used the external relief valve but those pumps are configured differently than the 68+ pump. The 1968 pump is not too difficult to find.
For NCRS judging you want a pump dated within 6 months prior to the car's build date.
The pump bracket was GM #3923214. This number also appears on the bracket.In Appreciation of John Hinckley -
Re: *** '68 AIR Pump Question ***
This is what an NOS example of the 1968 pump looks like. This one is julian dated "2568" (256th day of 1968 or September 12, 1968)[not for sale]. The pump backing plate of all 1968 pumps will carry casting number 7801149. This same plate was used for all 1968 to 1975 pumps, but not for 66-67 pumps.In Appreciation of John HinckleyComment
-
Re: *** '68 AIR Pump Question ***
WOW - thank - you, Joe for posting the pictures of an AIR pump. That is awesome. I only wish I could enlarge the pics for a closer detailed look. But at least I now know the correct part # for the pump. This helps me out immensely - I know now what to look for. I appreciate your time on this matter. Take care. BK
I also assume there is a GM # for the pulley - is 3925522 the correct one I should be looking for??? Thanks, BKComment
-
Dick WhittingtonComment
-
Re: *** '68 AIR Pump Question ***
Please note the finish of the die cast aluminum body of this pump (first two pictures). This is what a real 1968-1972+ finish should look like. You will not get this finish from many (any?) professional restorers.
I think the mid-year AIR pumps should have this same finish, but I will defer to someone with more knowledge on THAT subject than myself.
Edit add: The date of the AIR pump assembly relates to the body build date (trim tag date, or birthday book if you want/need to believe that reference) since it was installed on the engine at St Louis. The AIR pump assembly date has NO relationship to the engine assembly steel stamped date.TerryComment
-
Re: *** '68 AIR Pump Question ***
Terry, that is an excellent point on the aluminum finish. The same comment holds true for the alternators too. It is sad to see the accepted and so called "restored" condition by professionals on the show field.Comment
-
Re: *** '68 AIR Pump Question ***
Joe and Terry was this same pump used on the small block engines ??? I see part # 7801135 in the TIM/JG for 1968.Comment
-
Re: *** '68 AIR Pump Question ***
Yes same pump on SB or BB. Joe dealt with the only pump differences in his post above.
The TIM&JG (at least the newest version) reads: "The casting number 7801135 in 1968 and 7805650 in 1969 is under the fan and therefore neither visible nor judged." [Bold added by me.] This casting number is the pump casting number and NOT the one shown in Joe's photos. Joe's photos show the rear cover casting number which is far more visible when the pump is installed. Please note that neither number is a part number.
If I sound a little testy it is because this is a classic case of too much information just confuses = WTMI. Why did we add the invisible numbers to the TIM&JG and omit the visible numbers? My theory = just so we have something to do on this forum.
TerryComment
-
Re: *** '68 AIR Pump Question ***
Many thanks to all who took the time to reply - much appreciated. I definitely learned something here today.Comment
-
Re: *** '68 AIR Pump Question ***
Where would one find the white fan for the smog pump?Comment
Comment