1970 L/78 Nova open element air cleaner

[nuch_ss396]

I have a fast question for the Nova experts amongst us.

I know the '69 L/78 Novas used an open element air cleaner
and I believe it was the same base as the L/78 Camaro. I am
helping a friend with his 1970 L/78 Nova restoration and we
are wondering if the 1970 air cleaner base is the same as
the 1969 base. I've heard that the 1970 base is offset deeper to
facilitate hood clearance. That seems odd.

I believe that 68-72 Novas used the same SS hood,
so I suspect that the height between the top of the air
cleaner lid and the hood is the same. I also know that the
1970 L/78's used the lower height intake. What I don't know
is if the higher height intake ( 3933163 ) will fit under
the 1970 Nova hood if we use the open element air cleaner
base from a 1969 L/78 Camaro/Nova.

Can anyone set me straight? Is the 1970 L/78 open element
air cleaner base indeed different that the 1969 L/78 base?
BTW, I do know that the 1970 L/78 base uses a different angle
on the tube that connects to the passenger side valve cover.

Steve

[Mr70]

.."What I don't know is if the higher height intake ( 3933163 ) will fit under the 1970 Nova hood if we use the open element air cleaner base from a 1969 L/78 Camaro/Nova."

Yes,as long as you stick with that 69 OE Air cleaner.
You are essentially using the same ingredients as Chevrolet did building the 69 Super Sport Nova.

That low rise OE Air Cleaner,part #6423907,was used on virtually all chevy big blocks from 1966-1969,including the 69 Z/28 w/2nd hood design.In 1970,they changed to the new OE design,part #6485257,to sit higher off the new low rise intake manifold.

[CamarosRus]

Rick, What Open Element part # can be bought from G.M. or Paragon etc that can be used on the 70 Camaro 569 Intake/ Holly application.........
The Dual Snorkel really stifles and air flow and performance. I have ridden in 70 L-78 Camaro with and w/o Dual Snorkel and expereinced this first hand..........

Thanks,

[Mr70]

I wish I knew Chuck.
I see many aftermarket suppliers listing their standard Open Element reproduction air cleaners as fitting 1966-1973 Big Blocks.
Seeing as there IS a difference between the one they issued from 1966-69 vs.the one they issued in 1970,I'd say make sure you save the receipt.

I show these suppliers admitting they carry the repro 1966-1969 design now.
Part #6423907:
*MODERN CHEVROLET 800-722-4828
*CRAIG MOTORS 800-224-8111
*PACIFIC CORVETTE 800-228-2857

[nuch_ss396]

[ QUOTE ]
...That low rise OE Air Cleaner,part #6423907,was used on virtually all chevy big blocks from 1966-1969,including the 69 Z/28 w/2nd hood design.In 1970,they changed to the new OE design,part #6485257,to sit higher off the new low rise intake manifold.

[/ QUOTE ]

So Rick,

The pre-1970 open element bases were lower ( due to increased
intake height ) and the 1970+ were higher ( due to reduced
intake height ). Does that about cover it?

BTW, what the he-double-toothpicks is a 2nd design Z/28
hood? You're not referring to the ZL/2 hood are you?

Steve

[Mr70]

"The pre-1970 open element bases were lower ( due to increased
intake height ) and the 1970+ were higher ( due to reduced
intake height ). Does that about cover it?"
....Bingo!

No..the ZL/2 Cowl Ind. hood & AC was not the same as the flat hood used with the OE AC.I've heard reference to the second design Z/28 hoods,but I'm not really that familiar with them...rib structure maybe?
This is 1st gen Camaro mecca,so someone else here should know for certain.

[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...........