1970 L/78 Nova open element air cleaner

[USER-3965175]

THE 1970 L34 L78 AND LS6 6485239 OPEN ELEMENT AIR CLEANER ASSEMBLY USED ON 1970 SS 396 CAMARO’S – SS 396 NOVA’S AND SS 396 454 CHEVELLE’S USED THE SAME BASE AS THE 1967-69 6423907 AIR CLEANER ASSEMBLY BUT WITH A DIFFERENT VENT TUBE THAN THE 6423907 AIR CLEANER ASSEMBLY - THE 6485257 IS THE BB DUAL SNORKEL AIR CLEANER ASSEMBLY

WHEN THE 1967-69 6423907 AND 1970 6485239 BASES ARE PLACED SIDE BY SIDE IT IS EASY TO SEE THAT THEY ARE IDENTICAL BASES EXCEPT OF COURSE FOR THE VENT TUBES

BOTH BASES HAVE THE EXACT SAME STAMP MARKINGS AND INDENTATIONS ALL IN THE SAME EXACT LOCATIONS - EACH BASE HAS 3 DIFFERENT POSSIBLE VENT TUBE PADS IN THE SAME LOCATIONS - THE LOCATION WHERE THE VENT TUBE IS LOCATED IS THE SAME ON BOTH BASES - THE EXACT SAME INDENTATIONS FOR CLEARANCE ON THE CARB BOWL AND FLOAT ADJUSTING SCREWS ARE ON BOTH BASES - THE ALINGMENT TABS FOR AIR CLEANER TO CARB ARE THE SAME ON EACH BASE - THE TWO BASES ARE IDENTICAL

BOTH AIR CLEANER BASES HAVE A DEPTH MEASUREMENT OF 2” FROM WHERE THE AIR CLEANER SETS ON TOP OF THE CARBURETOR TO THE BOTTOM LIP OF THE AIR CLEANER BASE, WHICH MEANS BOTH AIR CLEANER BASES WILL RIDE AT THE SAME HEIGHT

THE HEIGHT OF THE INTAKE MANIFOLD EITHER A HI PROFILE OR LOW PROFILE INTAKE MANIFOLD HAS NOTHING TO DO WITH THE RIDE HEIGHT OF THE AIR CLEANER BASE

ALL AIR CLEANER BASES MUST CLEAR THE FRONT AND REAR HOLLEY CARB BOWLS AND ANY MOVING PARTS ON THE CARBURETOR – THE CARBURETOR SETS THE RIDE HEIGHT FOR ALL AIR CLEANERS NOT THE INTAKE MANIFOLDS

THE VENT TUBE USED ON THE 1970 6485239 AIR CLEANER COMES OUT STRAIGHT AT THE BASE FOR 1½” AND THEN BENDS AT A 90 DEGREE ANGLE AND ENTENDS STRAIGHT OUT PASS THE LOWER LIP OF THE BASE 1”

THE VENT TUBE ON THE 907 BEGINS TO ANGLE AT ABOUT ¾” OR SO WITH A 45 DEGREE ANGLE AIMING DOWN TOWARDS THE INTAKE MANIFOLD BUT STOPS AT THE OUTER LIP OF THE BASE

THE VENT TUBE IS THE REASON FOR THE PART NUMBER CHANGE FROM 6423907 TO THE 6485239 AIR CLEANER USED IN 1970 WITH THE ONLY DIFFERENCE BEING THE SPECAIL VENT TUBE

THE HEIGHT OF THE INTAKE MANIFOLD DOES HAVE AN IMPACT ON THE VENT TUBE HOWEVER - THIS IS WHY FOR 1970 THE 396 454 LOW RISE 3963569 INTAKE MANFOLD REQIURED A LONGER VENT TUBE WITH MORE ANGLE COMPARED TO THE VENT TUBE USED WITH THE
67-69 396-427 HI RISE INTAKE MANIFOLDS

THE 1970 6485239 AIR CLEANER ASSEMBLY LISTED IN THE FOLLOWING ASSEMBLY MANUALS SHOWS A PERFECT DRAWING OF THE VENT TUBE USED WITH THIS AIR CLEANER ASSEMBLY:

CAMARO ASSEMBLY MANUAL – UPC L34 SHEET A7
NOVA ASSEMBLY MANUALS – UPC L34 SHEET A6
CHEVELLE ASSEMBLY MANUAL - L34 SHEET A7 L78 SHEET A8

HOPE THIS CLEARS UP THE MISCONCEPTION ABOUT THE 1970 6485239 AIR CLEANER ASSEMBLY

M21RSZ28

[Mr70]

You're right,I was wrong.
That 1970 Open Element is #239,not the #257 which is actually the Dual Snorkle AC.
I agree with the vent tube issue,but have a few different OE's here that I always believed to be were from 69 vs. 70 cars.
I've seen many BB 70 chevys with incorrect OE air cleaners that just sit atop the carb/intake way to low and have a different dip measurement at the collar.
Maybe foreign knock offs?

[CamarosRus]

M21RSZ28, Your info and explanation is most welcome by myself, and certainly other members. You have now joined and added info here as well as at www.nastyz28.com.

Do you have an opinion on the quality of the 907 repro A/C that some parts vendors sell??

Is it conceivable that a source to be found to replicate the 239 Vent tube so as to retrofit the 907 with the 1970 vent tube.

Would you offer an opinion on the repro chrome lid that many people use to replace the 70 Z-28 and Dual Snorkel L-78 (257) lid ????

Below are three pics of three different 1970 L-34 Camaros showing ORIGINAL 239 Open Element A/C's








Thanks,

[CamarosRus]

M21RSZ28, I also would like your opinion on........when the 1970 Nova L-78 stopped using the 239 Open Element and switched over to the Dual Snorkel 257. Did Jan 1st, 1970 and any new EPA rules have anything to do with my thinking.
Also was there a similar situation with Non Cowl Induction Chevelles switching from Open to Dual Snorkel???

Thanks for your insight...........

[WILMASBOYL78]

[ QUOTE ]
M21RSZ28, I also would like your opinion on........when the 1970 Nova L-78 stopped using the 239 Open Element and switched over to the Dual Snorkel 257. Did Jan 1st, 1970 and any new EPA rules have anything to do with my thinking.
Also was there a similar situation with Non Cowl Induction Chevelles switching from Open to Dual Snorkel???

Thanks for your insight...........

[/ QUOTE ]

Chuck, my 3rd week jan/70 L78 Nova still had the original air cleaner base when I got it...so the change came after that...tw

[CamarosRus]

Tom, Very interesting to hear about your O1C Nova L-78. I'm just interested to learn when the Nova changed over to the Dual Snorkel and Chevelle for that matter.
I have NO Doubt that all 70 Camaro L-78's came with the Dual snorkel. The Dual Snorkel is the only L-78 A/C shown is 70 assy manual. My O1C Norwood Camaro has the Dual Snorkel.....

Many thanks Tom for your Nova 78 knowledge.........

[L78steve]

I've heard the dual snorkel change over came along late Feb.with the fuel return line and the exhaust resonators.Does this sound correct?

[USER-3965175]

I do not base my answers on opinions - everyone has one, right or wrong – opinions can lead to an incorrect conclusion. I base my answers on as much information as I can gather from either original cars or information by GM

I don’t have any information on Nova’s or Chevelle’s for a time line on Open Element vs. Dual Snorkel Air Cleaner usage

Build Sheets from September 1969 thru June 1970 would give a detailed history and would provide the best of the best for an accurate time line for Open Element vs. Dual Snorkel Air Cleaner usage

M21RSZ28

[nuch_ss396]

If you need a dual snorkel air cleaner for the L/78 Nova
or Camaro, or Chevelle - pucker up!

Just ended dual snorkel air cleaner eBay auction

[nuch_ss396]

Louis,

Thank you for that in-depth explanation of the two open
element air cleaners I asked about. I have a 69 & I can
locate a 70 base if needed. I can confirm that the tube
on the 70 version is indeed different that the 69 version.

So, I guess we will go with the 70 base and be done with it.
BTW, while on this topic, are the chrome lids to the open
element air cleaners any different between years? I suspect
not, but I should ask to be thorough.

Also, I ditto the request regarding the repro units. I'd sure
like to know if they are different ( wrong ) as well.

Steve