C2 Interior and Smog question- not related

**Joe L.** · May 4, 2003, 11:06 PM

Re: C2 Interior and Smog question- not related

Mike----

Personally, I think that Al Knoch has the best interior parts currently available. The "Imco" refers to the logo on the heel pad of Corvettes originally so-equipped. "Imco" is an acronym for Interstate Manufacturing Co. which made most of the original heel pads. These are available on carpets manufactured today by Romeo Engineering. I've heard some folks say that they've had delivery problems with them.

As far as the smog questions go:

1966 AIR pump, 327 and 427= GM #5697255

1967 AIR pump, 327 and 427= GM #7800308

1966 mixture control valve, 327= GM #7036195 (may be identified on valve by "36195")

1967 mixture control valve, 327= GM #7033546 (may be identified on valve by "33546")

1966 and 67 mixture control valve, 427= GM #7033547 (may be identified on valve by "33547")

There is a difference between the calibration of the 327 and 427 valves. If there were no difference, at all, in the valves, they would not have different part numbers. A one number difference in the part number can mean a BIG difference in the part.

AIR pumps usually do not have any identification as to the assembly part number. The castings which comprise the unit may have visible casting numbers but this does NOT identify the pump with specificity (i.e. the same castings may be used for a variety of finished pumps).

**Tom R.** · May 5, 2003, 04:37 AM

Re: C2 Interior and Smog question- not related

Joe:

While you've got the parts book out...check on a 5696132 pump and thanks.

**Joe L.** · May 5, 2003, 12:31 PM

Re: C2 Interior and Smog question- not related

Tom----

I can't find any record, at all, of that part number. If it was a part number for an AIR pump ASSEMBLY, then it was never used on a Chevrolet. I don't think that it was used on any other GM car, either, but that's a possibility.

**Tom R.** · May 5, 2003, 04:28 PM

Re: C2 Interior and Smog question- not related

It's appearance is one before 1970 with the air hole looking like those on a 68-69 car...which always reminds me of a colostomy.

**Joe L.** · May 5, 2003, 05:36 PM

Re: C2 Interior and Smog question- not related

Tom-----

Is this number somehow stamped on a component of an assembly or is it a number stamped on a box with the part in it? A SERVICE part box is about the only place that you'll find the part number for a smog pump assembly.

By "air hole" if you are referring to the air pressure relief valve on the pump housing, these were used for 66-68 pumps and 1969 L-88/ZL-1 pumps only (which used the 68 style AIR system). They were not otherwise used for 1969 pumps.

**Tom R.** · May 5, 2003, 06:51 PM

Re: C2 Interior and Smog question- not related

Yes to the air hole on 66-68 pumps. The number is stamped on the end casting as you would find with a 7801149...which sits next to it.

Date code 03911A with the 0 barely discernable. Stamp was heavy on the A end and located on the half moon protrusion on the casting as on the 7801149 unit.

On the other end from the 5696132 is the words "do not clamp in vise" and a number 5696211 with CFB4 underneath it and CK circled.

**Michael S.** · May 5, 2003, 07:58 PM

Re: C2 Interior and Smog question- not related

Joe and Tom-

The number on my smog pump is also 5696211 with CFB4 underneath it. The pump is the proper configuration for 1966 and 1967-at least as far as I can tell.

Is this the proper unit or am I missing something ?

Also, any good sources for mixture control valves out there ?

Thanks.

**Tom R.** · May 5, 2003, 08:10 PM

Re: C2 Interior and Smog question- not related

Hey Mike:

So that's the number on the aluminum casting...what about the other side? What's the number on the black plate?

**Joe L.** · May 5, 2003, 09:25 PM

Re: C2 Interior and Smog question- not related

Tom-----

The numbers which you mentioned are the part numbers for the end plate and the pump housing, respectively. I cannot ID the pump from these numbers. The same basic castings may have been used for many finished pump assemblies. I'd venture an educated guess that we're talking about a 66-67 style pump. However, these pumps were used on many GM cars besides Chevrolet and I have no way of knowing if this ASSEMBLY was Chevrolet, or not. The part numbers are Saginaw or Delco.

The 66-67 Corvette pumps were unique in that the outlet hoses came off of a "T" that attached to the bottom of the pump housing. Most other pumps have the outlets off of the back plate. Some Corvette back plates have soft plugs in the outlet orifices used for other applications and some have the back plate unmachined for the orifices, but the bosses are there.

**Bob Grauer** · May 6, 2003, 10:07 AM

Re: C2 Interior and Smog question- not related

Mike,
My 1966 "IM" 427 still has it's original smog pump and diverter valves
on it. If you need any pics, just let me know and I can send some digitals.
I have never seen another 1966 diverter valve offered for sale and I always look for them. There is a part number on the back side along the rim and I can shoot a pic of that as well if you like.
There is a T junction on the bottom as well as the hole in the back, plus pumps are dated. I wrote a Restorer article describing the entire system in 1998-1999. You might look for that too.
Bob Grauer

**Michael S.** · May 6, 2003, 07:55 PM

Re: C2 Interior and Smog question- not related

left to right numbers and letters are *D8 154 5696132

**Michael S.** · May 6, 2003, 07:59 PM

Re: C2 Interior and Smog question- not related

thanks Bob, I think I am all set with what I need, finally. I found a NOS diverter valve and a used, proper numbers. If these come through and are proper and work, I would be happy to sell you the 427 mixture control valve I have GM#7033547 as it is not much good for my 327. You can email me privately, I just need a few weeks to see if the system installs and works. Car is being primed currently.

**Tom R.** · May 6, 2003, 08:20 PM

Re: C2 Interior and Smog question- not related

Mike:

Interesting. If you have the Winter 90 edition of the Restorer, it has Bob's article which refers to the 66 pump. The number he reports is the 5696132 on the black phosphate end plate. Ironically, the *D8 5696132 is identically to the pump I've got except the middle three numbers (154). The pump I'm looking at is 239. According to Bob's article, the D8 is the date code and probably refers to April 68 but there is also another number if you look on the flange on the cast aluminum. Look at the half moon shaved portions and you should find a number...something like 03911A (the pump I've got). It suggests a date code of 39 day in 71. So, you can see there is some inconsistency and I'm not familiar enough with late 70's to decode.

**Bob Grauer** · May 7, 2003, 10:09 AM

Re: C2 Interior and Smog question- not related

The date coding on my pump is 03561E.
That means 35th day of 1966, control/shift 1E.
All 66 & 67 pumps read this way with the 4th digit the year.
The pump is not a 71, but a 67...
Bob

C2 Interior and Smog question- not related

C2 Interior and Smog question- not related

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