Is This 67 Air Cleaner Base Original?

[John H.]

Re: Is This 67 Air Cleaner Base Original?

The base on my 67 327/300, S/N 15586, looks just like the one in Brian McHale's photo. In other words, it has the third depression in the location indicated in your photo.

Mine (#20401) does too.

[Kirk M.]

Re: Is This 67 Air Cleaner Base Original?

My sense at this point is that the base in my pic without the depression would be correct for 66 and the one with the depression would be correct for 67. My only hesitation might be that the 66 without depression was used on early production 67's. Anyone got one they can check for us?

Kirk

[Timothy B.]

Re: Is This 67 Air Cleaner Base Original?

Kirk,

I have a 1967 roadster 327/300 built September 66 and I believe correct air cleaner. I will get pictures later today and post tonight or tomorrow.

I also have a 70 LT1 air cleaner that has the three indentations and the arrester/vent tube is installed in one of the three but different location.

[Neal K.]

Re: Is This 67 Air Cleaner Base Original?

Tim,
Did you every verify if your Sept 66 production 327 had the air cleaner with the 3 depressions on the passenger side of the base.
I have an early Sept production L-79 and I think I have the wrong base since it has only 2 depressions.
Thanks
Neal

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

Neal,
I think he did on this thread...you are OK IMHO...

https://www.forums.ncrs.org/showthread.php?t=84019

[Russ S.]

Re: Is This 67 Air Cleaner Base Original?

I have an original base that has the third hump. I purchased this base at a swap meet thirty years ago -before there were any repos. I bought this base for my 66 and had it on the car. I also have a second base (which I tried to sell at a swap this past weekend) which does not have the third hump. Thanks for this post Kirk- I now need the one I was trying to sell for my 66.

[Lou C.]

Re: Is This 67 Air Cleaner Base Original?

Is this a 67 base?

[Timothy B.]

Re: Is This 67 Air Cleaner Base Original?

Check the archives, there is a recent post on the subject in the past month.

[Russ S.]

Re: Is This 67 Air Cleaner Base Original?

Is this a 67 base?

I would say it is from the pics and above discussion.

[David L.]

Re: Is This 67 Air Cleaner Base Original?

Is this a 67 base?

Lou,

It looks like a 67 base for 327 assuming the tube is correct. Enclosed are photos on a 66 base for 327 (top & bottom views). The 67 base has the extra indentation.

Dave

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

The key to look for on the tube is the wall thickness, the original is .035 - .040.

The reproduction.... .065-.070 and the nipple is not formed correctly either.

[Scott S.]

Re: Is This 67 Air Cleaner Base Original?

Gentlemen,
It appears the base is from a 66 sb PRODUCTION car, starting in 1967, Chevrolet starting using Quadrajet carbs on some car models using this same base, the additional clearance "hump" is for linkage clearance on the quadrajet. I think it will be found on all 67 up cars and all service or repo bases from then on, hence, that base is a 65-66 small block AND big block production line base only (was service also until end of 66), the sb and BB difference being the location of the vent tube, I have seen a couple of different versions of the tube, basically same, just probably a different supplier. Does anyone know of a changeover date? Maybe the corvette base was kept separate in manufacture from other models? Soon I am sure this will wind up in the JM , it has never been reproduced. I think it would be possible to find one on any 67 car, probably earlier than late but who paid attention? Can anyone come up with a different part number from a GM parts manual? I have pics available of both sb and BB versions for 65 396 and all 327 and 427 1966 cars. Hoping someone can add to this or owners check their bases and post their findings?
Bill

Bill,

It looks like the small block air cleaner base in question is GM 6422931. It first appears in the Oct. 1965 printing of the 1966 P&A catalog, Group 3.406:
66 Corvette (exc. 427) . . . Base Assy. (w/6422286) . . . . 6422931

The Oct. 1966 printing of the 1967 P&A shows the exact same listing (no mention of 1967 model year, only 1966), except the price actually dropped a dollar to $12.50

For the Oct. 1967 printing of the 1968 P&A onward, the 1967 model year is included, and the associated 1967 AIM Air Cleaner ASSEMBLY part number (6423909) is added:
66-67 Corvette (exc. 427) . . . Base Assy. (w/6422286-3909) . . . . 6422931

By 1972, three more Air Cleaner ASSEMBLY part numbers are added, and 6423909 is dropped:
66-67 Corvette (exc. 427) . . . 6422931 . . . (w/6421816-2286-3240-3907)

The 1972 listing information remains the same through at least 1977.


Based on this information, and the observed differences in photos of original 1966 and 1967 Corvette small block air cleaner bases, it looks like the part was altered to include the additional indentation for 1967 without ever changing the GM part number.

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

I am sure this detail is located in another thread, however 66SB was a one year wonder save the first few weeks of 67 MY SB production.

The die that stamped the base plate for both SB BB was changed in August 66 and did not get completed in time - or - the left over 66 SB stock was used up on the early 67 SB cars. The other thread has a number of examples of this cited.

[Scott S.]

Re: Is This 67 Air Cleaner Base Original?

I am sure this detail is located in another thread, however 66SB was a one year wonder save the first few weeks of 67 MY SB production.

The die that stamped the base plate for both SB BB was changed in August 66 and did not get completed in time - or - the left over 66 SB stock was used up on the early 67 SB cars. The other thread has a number of examples of this cited.

Ron,

If you are referring to the link you referenced in post 20, it was a good re-read, there were more posts at the end which I must have missed last time around.

The air cleaner base is not listed as a separate part of the Air Cleaner Assembly in the AIMs, but it is listed as a separate part in the P&A books. In this case, unless it is listed under a different Group than all of the other air cleaner base plates, I can find no evidence that the air cleaner base part number for 1966-1967 small block ever changed, even though quite clearly the part itself was changed. The books show the GM 6422931 air cleaner base part number beginning with the October 1965 printing of the 1966 P&A, before any configuration change in the air cleaner base was conceived of.

This same GM 6422931 air cleaner base part number for 1966 small block was then applicable to 1967 small block (but no other Corvette engines besides 1966-1967 small block), and continues that way in all of the P&A books through at least 1977, part number unchanged, even though we know the part itself was altered sometime in late 1966, approximately a year after it's part number was established in the October '65 printing of the P&A for the 1966 model year.

Clearly the part configuration changed, as the photographs show.

It appears that the part number did not change.

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

Scott, This is a typical case where the service part books lead one astray, the prints and aims are the source documents that determine what was correct & when.