Is This 67 Air Cleaner Base Original?

[Scott S.]

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.

Hi Ron,

Assuming then that GM 6422931 is the correct part number for the original 1966 small block air cleaner base, since it came into being and was numbered circa October 1965, before the version with the extra indentation was created, what does the GM blueprint show the "after alteration" part number to be, i.e., the part number that should have been listed in the P&A for the air cleaner base with the extra indentation added for model year 1967?

[David L.]

Re: Is This 67 Air Cleaner Base Original?

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.

Scott,

I have done research on the 1966 and 1967 small block air cleaner bases with my vintage Chevrolet parts catalogs and have come to the same conclusion as you. GM added the extra indentation to the 1967 base and did NOT change the part number.

Dave

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

Dave, print change only.

[Scott S.]

Re: Is This 67 Air Cleaner Base Original?

Dave or Ron,

Do either of you know what the deal is with the BB air cleaner base? The 67 AIM calls out GM 6423910 for the L88 (UPC L88-A4), which the 1968 P&A says is the same air cleaner base for all Corvette big block engines (65-67 with 396 or 427, and 67-68 w/H.D.), but Dobbins p. 279 says the L88 air cleaner base had no flame arrestor, and the photo shows that there's not even a tube opening to attach a flame arrestor, so it can't be the same air cleaner base as used on other 427s.

[David L.]

Re: Is This 67 Air Cleaner Base Original?

Scott,

My 1967 Chev. Parts Catalog (Apr. 1967) lists GM # 6423910 in Gr. 3.406 as the base for the 1967 Corvette w/H.D. 427, nothing else.

Dave

[Scott S.]

Re: Is This 67 Air Cleaner Base Original?

Scott,

My 1967 Chev. Parts Catalog (Apr. 1967) lists GM # 6423910 in Gr. 3.406 as the base for the 1967 Corvette w/H.D. 427, nothing else.

Dave

Thanks Dave. My Oct. 1966 printing of the '67 P&A does not list any BASE ASSY. for 1966-67 big block, at all. It shows GM 6422188 for the '65 with 396, but nothing for 66-67 with 427. The Oct. '67 printing of the 1968 P&A is where it shows GM 6423910 Base Assy. applicable to 65-67 with 396 or 427, and 67-68 w/H.D., and again in the '69 P&A, but not after that.

Which begs the question, if GM 6423910 was the L88-only air cleaner base, then what was the "standard" air cleaner base part number for 1966 and 1967 big block? My '66 P&A doesn't list anything for a '66 with 427 either, just the GM 6422188 base for the '65 L78. Did the '66-67 BB (exc. L88) use the same air cleaner base as the L78?

[Ronald L.]

Re: Is This 67 Air Cleaner Base Original?

396 base carried over to 66, AUG 66 The part got the extra dimple it was a print change with no part number change.

[Scott S.]

Re: Is This 67 Air Cleaner Base Original?

396 base carried over to 66, AUG 66 The part got the extra dimple it was a print change with no part number change.

Thanks Ron, 1-1/2 years with no listing for a 427 air cleaner base, during those model years' production (66-67), seems like a long gap in the P&A record for such a part...

[David L.]

Re: Is This 67 Air Cleaner Base Original?

Scott,

According to Chev. Parts History GM # 6422188 was replaced with 6423910 in Aug. 1967 for over-the-counter parts. Then, GM # 6423910 was replaced with 6423910 in Nov. 1968.

Dave