[HO LEMANS]

I can't seem to locate the information I am looking for so again I turn to you guys for help ( which is always greatly appreciated) 2 things what does the factory 390 hp 428 HO air cleaner look like and does anyone have the correct part number?

Thank You
H.O.

[steve25]

It should be a duel snorkel with a chrome lid like this.

68 and 69s looked the same, but for some reason where different part numbers.

[OG68]

The '68s had a single snorkel air cleaner for all V8, non RA models including the 390 HP 428 IIRC. Might explain the different part number.
Photo is from the 1968 Performance brochure.

[TXSTARFIRE]

My 7-73 MPC shows P/N 6424827 Air Cleaner used on all 68 428 and 69 428 HO in full size cars. This number was also used on 68 Firebird and Tempest with 400 4 B.C., 69 Firebird with 400 4 B.C., and 69 Grandprix with 428. This should be the dual snorkel air cleaner. The only different P/N for 428 is the 1969 non HO used in big cars which is P/N 6485501. This number was also used on 69 400 GPs, 68 and 69 big cars with 400 4 B.C. and 68-69 Firebird and Tempest with 350 4 B.C. This should be the single snorkel air cleaner. Of course parts books are not always correct.

[TXSTARFIRE]

Was 1969 the first year for dual snorkel air cleaners? If so it could be that the 69 specific dual snorkel air cleaner was no longer available by 1973 and was substituted by the single snorkel unit which would explain the applications listed in my MPC. If air cleaners are shown, maybe the assembly manual is the place to look for this info.

[1969GTO]

Good luck trying to find a nice condition reasonably priced single snorkel.

[OG68]

Also remember that the 69 dual snorkel was different than the 70 which in turn may be different from the 71/72. If my eyesight isn't deceiving me, it appears that the 71/72 had a different design snorkel. Could someone clarify that?

Anyone know why the dual snorkel wasn't available on the 69 Firebird? Not enough room?

Most of the singles, and duals, have damaged snorkels.. You can get a somewhat decent priced single snorkel if you're willing to rework the snorkel intake. It's not hard to do, but takes a lot of patience and the use of a radius gage.

The hot air doors (Auto-ThermAC) are still available.

Photo courtesy of Dataway

[SD455DJ]

Originally Posted by HO LEMANS

I can't seem to locate the information I am looking for so again I turn to you guys for help ( which is always greatly appreciated) 2 things what does the factory 390 hp 428 HO air cleaner look like and does anyone have the correct part number?

Thank You
H.O.

Fair warning…there’s a ton of applications to digest here! The ’68-’69 428 HO air cleaners used on B-body & GP’s is a single large snorkel unit also found on 4-bbl high performance engines (except ’68 Ram Air engines in GTO’s & Firebird 400’s). There are several part numbers and codes for each engine (L76 350 HO, L74/L78 400 4-bbl, L79 428 4-bbl; L75 428 HO), however, L75 428 HO’s use PN 6424826/6424827 (with & without K45 HD air filter).

(The ’69 GTO standard engine (WT/YS code 350 hp) was the first use of the dual large snorkel air cleaner PN 6484993/6484994) that didn’t have the California emissions carb bowl vent hole. The Firebird 400 base and HO along with the GP 400’s, still utilized the single large snorkel air cleaners. The ’70 – ’72 dual large snorkel air cleaners with PN 6485778 with the vent hole…plugged for non-CA use.) The ’70 GP/B-body base 400 4-bbl was equipped with the single small/short snorkel air cleaner.

The attached snip from the ’75 Parts Catalog no doubt contains superseded part numbers and appear to have dropped the PN’s for the air cleaner assemblies with the KL45 HD Air Filter for simplicity.

Dennis

[HO LEMANS]

SD that is some great information (alot to digest as you said but interesting for sure) I do have a question that I am confused on if you type the part number 6424827 into google it shows a bunch of dual snorkel air cleaners but the info here shows it to be a chrome lid single snorkel and the duals are 6484993/994 or 6485778 so I have to admit I'm lost I guess for what I'm doing it's not critical to have the "exact" air cleaner but the 6485501 that I currently have will be replacing the missing air cleaner on my 350H.O. so I want to get a replacement 428H.O. air cleaner (honestly I prefer the single snorkel but will be happy with either)
Thank You again for the great info

[HO LEMANS]

OG68 that's some good info and yes I have done the radius gage thing with air cleaners and it tested my patience for sure

['ol Pinion head]

The dies that were used to stamp the snorkel changed during '69 production. The snorkel used on the '68 GTO-Firebird 400/428HO B series aircleaner (& the '68 Olds 442 aircleaner base) will have a thin long raised line across the snorkel. This detail carried on onto early '69 model 428HO aircleaner bases & on early ' 69 usage Firebird 400 bases, as well as on dual snorkel wide spread '69 GTO aircleaner bases. By mid '69 production this minute detail was gone, with the top of the snorkel being totally flat.

As mentioned above No Dual snorkels bases installed on '69 428HO B series or for that matter '69 Firebird 400's. would have to double ck, but believe the B series & GP's equipped with Instant Air option. the valve and bracketry interfered with pass side snorkel on a '69 GTO dual snorkel base.

[SD455DJ]

Hey Roger! Welcome back! I never noticed that raised 'band' that goes around the snorkel that matches the width of the heat stove on the bottom and the Auto-Therm AC actuator on the top before. It is very subtle, but you can see it in the reflection on the side of the snorkel.

Dennis

[HO LEMANS]

ok guys I truly am not trying to be a P.I.T.A. with the questions but does anyone have an actual photo of the 6485501 air cleaner I think I have one but there are no part number decals on it and I am not seeing anything stamped (if it is stamped where do I look for that?)

Thank You everyone

[SD455DJ]

Originally Posted by HO LEMANS

ok guys I truly am not trying to be a P.I.T.A. with the questions but does anyone have an actual photo of the 6485501 air cleaner I think I have one but there are no part number decals on it and I am not seeing anything stamped (if it is stamped where do I look for that?)

Thank You everyone

Here you go...'69 350HO Firebird.

Dennis

[HO LEMANS]

Originally Posted by SD455DJ

Here you go...'69 350HO Firebird.

Dennis

well Dang I guess the one I have is NOT 5501
I was hoping the original from my 69 428 was the correct one but nope

Thank You Dennis

[SD455DJ]

I don't believe there are any visible & physical differences between them all, other than the chrome lid as well as the filter type, with or without HD Air Filter (which had different numbers, 6424826/6424827 with the chrome lid). The 6424824/6424825 had the black lid on the L79 428's.

Dennis

[Bruce Meyer]

For reference. This air cleaner came off of a 68 Firebird 400. The part # is BC 6484022.

[Held for Ransom]

I thought Ken had the codes for the air cleaners. https://forums.maxperformanceinc.com...&postcount=152
The 5500/5501 had a black lid while the 4826/4827 had a chrome lid. Inside of base may have had a diffuser welded at the snorkel opening. Otherwise all should be similar. At some point in '69 they went to a decal instead of the silkscreen.

[HO LEMANS]

The one on my 69 428 (which I was hoping was the 5501 for my 350 H.O. Lemans) looks like this one with the smaller snorkel w/black lid ....

[android 211]

Check out Jay Leno's Garage; he drove a '69 Grand Prix 428 4 speed. The owner said it was the 370 hp motor and a 390 hp version was available. No a/c with 390hp. Dual snorkel air cleaner wasn't put on the GP but you can if you want and no one will fault you. Chrome lid with 428, chrome valve covers too.