428 H.O. air cleaner
 

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.

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.

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.

https://forums.maxperformanceinc.com...5&d=1773791421

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.

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.

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

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

https://forums.maxperformanceinc.com...8&d=1773861454

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

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 :confused: 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

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

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.

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

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

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

Thank You Dennis

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

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

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.

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 ....

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.

Hmmm, you're right. I looked at a couple '69 Bonneville 428 engines and they have the small snorkel.
I'll look to see if I have something to take a picture of...

Found a couple from the engine that went into my old '69 Firebird convertible. Can't read tag.

Yep that's the same one my 428 has

Does it have the silk-screened P/N on it yet? Can you post a pic of it if it does?

Thanks! Dennis

I don't think it does but I will look later today and find out

This was either a 350HO or 400 Firebird air cleaner I bought from Bill's Birds back when I had my convertible and before the 428 swap. Again, can't read tag, but the newer tag instead of silkscreened one.

I looked at my air cleaner last night and it must of had a decal instead of a silk screen as there is nothing left on the sides but oily dirt ...

From what I've seen, the white external silk screen (not the sticker decal currently sold by the vendors) was used on '68 air cleaners. The white sticker was on '69s. But never both of them at the same time from the factory.

Makes sense to me as mine is a 69 and there is nothing there but oily dirt

As posted earlier by HFR, the '69 labels were silk-screened on early air cleaners and transitioned to the decal labels later in the year. My brother has a 56,000 original mile '69 350HO 4-speed Firebird with its silk-screened air cleaner (6485501 - PV) in place. My '69 350HO Custom S has the correct air cleaner I found locally as well (6485500 - PT). They are both earlier production cars (12/68) fitting that logic. Both have the correct P/N's for their applications as well. '68's had different P/N's for similar applications.

Dennis

Must have missed that. Thank you Dennis

You bet Ed! I'm still befuddled on what the P/N's are for the skinny single snorkel 4-bbl air cleaners, as all the one's listed are the large snorkel. I'm still trying to figure that out. My brother Dan's '69 428 Catalina/Ventura (YH code 428 w/small valves) has its original 'skinny' single snorkel air cleaner that must have had the decal P/N, but it's missing. The B-body small valve high compression (340 hp) 400's used the same one.

Dennis

I have some codes but not all. I keep an eye out for vintage photos or original examples on eBay for reference. If someone has the part number and code, I could likely put together a silkscreen. They're all reasonably uniform with exception of the two letter code and part number - even across makes and models.

He would be looking for the PT code shown in post #29 for silkscreen. But, I don't have a clear picture of the decal to show.

Oh, I do have a couple of those! I had them marked for a 350HO though :confused:

https://forums.maxperformanceinc.com...1&d=1775775082

Ken, PT is correct for the '69 350HO with the A212 AC filter. PV is with the HD A279C filter.

Dennis

I need one of these please :eek:
let me know how much to send you and how to send it :D

HFR I sent you a PM.... don't know if you got it or not .... if you did -- no response answers my question :D
If you haven't seen it please check it out

Dropped your silkscreen in the mail today : )

Thank you very much !
looking forward to the shirt as well :clap2::D

Received my hood tach shirt today and it is great a really nice shirt!! honestly thought the tach face would be smaller so I was really happy to see how big it was !
Thank You very much!!

received my shirt today and it's great a really nice shirt! honestly thought the tach face would be smaller so I was super happy to see how big it was !!
Thank You!!