# 1968 GTO HO air cleaner



## datahoarder (May 14, 2019)

Can somebody please let me know regarding the 68 GTO HO air cleaner.

Some say its the single snorkel the same as all other 68's others say it was an open element. My car was built late Nov 67.

Pionionhead states

"An original '68 400 HO GTO received an open element aircleaner, there was no Pontiac Q-jet dual snorkel aircleaner avail on '68 models, base 350 horse GTO's or 360 horse HO cars. "

The attached 1968 engine lineup shows a different air cleaner for the HO. The restoration guide says its the same single snorkel

If it is an open element anyone have a picture of this unit?


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## BLK69JUDGE (Jun 10, 2010)

68 HO cars had a single snorkel chrome topped air cleaner housing....

here is a low mile 68 yz car I had a few years back

those are just generic pictures in the description

Scott

just my opinion


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## PontiacJim (Dec 29, 2012)

datahoarder said:


> Can somebody please let me know regarding the 68 GTO HO air cleaner.
> 
> Some say its the single snorkel the same as all other 68's others say it was an open element. My car was built late Nov 67.
> 
> ...



I don't think you may have read the entire post? :nonod:

*Post #13 by Shake-N-Bake* - I believe all 1968 GTOs left the factory with a closed lid air cleaner with a snorkel tube. I believe all had a chrome lid and single snorkel but I suppose some late model builds could have received the dual snorkel model seen on the 69 models but those would be the exception and not the rule. At any rate, none were open element type.....not from the factory.

Ram Air cars _were fitted with_ (ie from the factory) the chrome closed lid snorkel air cleaner complete with heat riser tube and shroud. The open element air cleaner, ram air pans, foam seals and open element hood scoops shipped in the trunk. _Those parts were intended to be fitted to the car at the dealership._ The owner was expected to keep the original parts for use in inclement weather.....I doubt anyone ever reinstalled those items but that was the intended use. 

*Post # 17 by Pinion Head*- I do now realize the stock embossed line style single snorkel 350 horse engine aircleaner came stock on '68 400 HO (360HP) GTO's. I stand behind my descriptions of the embossed lines on the '68 4bbl GTO & Firebird 400 air cleaners discerning this style from later style wide snorkel air cleaners Pontiac used through the '70 model.

Hope that clears things up.


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## datahoarder (May 14, 2019)

Any body seen this before?


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## BLK69JUDGE (Jun 10, 2010)

hmmm
nope on the lettering ...
the base looks to be 71 72 ish wrong inlet for 68 69 70 4bbl maybe 70 big car 455
pop the top off and look for small green silkscreen julian date 1/4 inch high
3/4 inch wide

between air filter and carb hole...

is there a vent hole in the base ?

S T


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## PontiacJim (Dec 29, 2012)

datahoarder said:


> Any body seen this before?



Ya, I've see that kind of bogus stuff at swap meets. Hmmmm. What year did Pontiac use a sticker on their air cleaners that said GTO 400 HO? NEVER. Probably sat on top of a 326CI powered GTO clone that sold at the Mecum action for $42,000.

*BLK69JUDGE* has shown you a photo of the 1968 HO chrome topped air cleaner. Anything else is not correct. :nono:


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## integrity6987 (May 10, 2017)

PontiacJim said:


> Ya, I've see that kind of bogus stuff at swap meets. Hmmmm. What year did Pontiac use a sticker on their air cleaners that said GTO 400 HO? NEVER. Probably sat on top of a 326CI powered GTO clone that sold at the Mecum action for $42,000.
> 
> *BLK69JUDGE* has shown you a photo of the 1968 HO chrome topped air cleaner. Anything else is not correct. :nono:


Related question.....

1968 HO air cleaner. Inside the housing is a baby blue vacuum valve of some kind. It has two nipples protruding from the bottom. One line goes from it to the flap in the snorkel. The other inlet nipple from the underside of the air cleaner is not attached to any source. 1) do you know the source and 2) the function. My assumption is this is for cold weather so N/A for my need, but I can't find anything about it.


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## PontiacJim (Dec 29, 2012)

integrity6987 said:


> Related question.....
> 
> 1968 HO air cleaner. Inside the housing is a baby blue vacuum valve of some kind. It has two nipples protruding from the bottom. One line goes from it to the flap in the snorkel. The other inlet nipple from the underside of the air cleaner is not attached to any source. 1) do you know the source and 2) the function. My assumption is this is for cold weather so N/A for my need, but I can't find anything about it.


I did send you a reply to your message you sent me. Did you get it? It looks like the vacuum source is the carb? View next Reply.


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## PontiacJim (Dec 29, 2012)

Here is a diagram that may explain how it works.


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## integrity6987 (May 10, 2017)

PontiacJim said:


> Here is a diagram that may explain how it works.


Thanks PJ! -- I really like learning about the mechanical solutions the PMD/GM engineers implemented.


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## PontiacJim (Dec 29, 2012)

integrity6987 said:


> Thanks PJ! -- I really like learning about the mechanical solutions the PMD/GM engineers implemented.


Here is how it works - lower right of the page.

It was found that raising the cylinder temps helped reduce emissions. This was done by retarding the timing, raising engine temps by installing T-stats that kept the engine in the 195-200 degree range, and leaning out the carbs. This also raised under hood temps and the incoming air that went down the carb. 

The quench/squish area was becoming a concern around the early 1970's and combustion chambers were being redesigned (at least at Chrysler) to address this concern. The hotter incoming air/fuel mixtures and increased engine temps were said to vaporize the fuel better to minimize "the large cooling surface to the flame front." 

We all know what retarded timing does - increases engine temps and can hurt performance. We also know that a cooler (under the hood) incoming air mixture, ie Ram Air, helps slightly in the power department because the engine can be tuned slightly different for a little extra power, ie distributor advance and increased jet size in the carb (s).

We also know a lean A/F mixture can make the engine run hotter.

For our hobby, these are all bad things we try to fight off and adjust out of our engines so we don't get detonation or pre-ignition, or an engine that runs too hot most of the time. Many of us have to deal with the fuel percolation and/or evaporation, but guess what, the hotter running engines of the emission era beginnings experienced fuel percolation problems even with the ethanol free gas as well as engine "run on" when you shut the car off.

So have we really moved forward? Not on our older engines, but they sure have on the latest designs. It just goes to prove that our older engines will always be "old" in design and how they run............it's just how it is, period. You can't get them to be 2019 engines, so see them for what they are - gas guzzling, emissions abusing, finicky at times, rubber burning, loud sounding, smile making, nostalgia contraptions of the past gone by. And when those of us who own them die off.......the air will be sooooooo much cleaner. :thumbsup:


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## bkmont (Jan 1, 2015)

Hi guys don't post much but was curious about the air cleaner. My 68 has the original 350 hp WT motor. It has what i believe is the original air cleaner. You can see the before pic of when I picked up all the parts and the after pic when I cleaned up the air cleaner. Just to be clear, did all the 350hp motors come with the chrome air cleaner lid too?
Thanks!


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## Shake-N-Bake (Jun 16, 2015)

According to factory literature, all GTOs had the chrome air cleaner lid.









Sent from my SM-G930V using Tapatalk


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## PontiacJim (Dec 29, 2012)

bkmont said:


> Hi guys don't post much but was curious about the air cleaner. My 68 has the original 350 hp WT motor. It has what i believe is the original air cleaner. You can see the before pic of when I picked up all the parts and the after pic when I cleaned up the air cleaner. Just to be clear, did all the 350hp motors come with the chrome air cleaner lid too?
> Thanks!



Yes, one more time. ALL 1968 GTO's 350HP & 360HP used the SAME air cleaner with chrome lid unless.........

The Ram Air option was used.

The decal you have shown which may or may not be original or is a reproduction, is information for the Dual Stage, Heavy Duty Air *Filter*, Code 731. Dual *filter* consists of wetted paper in filter, surrounded by polyglycol wetted polyurethane foam outer filter. Available on all models except 428 HO. It was either factory or dealer installed.


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## bkmont (Jan 1, 2015)

PontiacJim said:


> Yes, one more time. ALL 1968 GTO's 350HP & 360HP used the SAME air cleaner with chrome lid unless.........
> 
> The Ram Air option was used.
> 
> The decal you have shown which may or may not be original or is a reproduction, is information for the Dual Stage, Heavy Duty Air *Filter*, Code 731. Dual *filter* consists of wetted paper in filter, surrounded by polyglycol wetted polyurethane foam outer filter. Available on all models except 428 HO. It was either factory or dealer installed.


Thanks! I believe the Dual Stage info is original. It is not a sticker. It appears to be screen printed and this car had been sitting up for 30 years.


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