Vortec Compatible Intake Manifold Under Stock '78 Z28 Hood

danbrennan

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Mar 13, 1999
4,963
Brighton, MI
Just curious, has anyone found an intake manifold, that fits to Vortec heads, that also fits under the stock '79-'80 hoods, with the stock air cleaner assembly? Street use only, so dual plane is okay.
 

Damon

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Nov 16, 2000
12,939
Philly area
Weiand Street Warrior line. It's lower than the Performer or Performer EPS.

It is NOT as low as stock (nothing is as low as the stock "pancake" QJet intake), but everything should still fit.
 

JONESYFXR

Veteran Member
Oct 10, 2009
2,177
BUFFALO, NY
I'd think that any dual plane non-Airgap intake will clear without issues. You could possibly use an Airgap style with a drop base air cleaner.

Contact Widowmaker01, I bought an Airgap style Professional Products intake from him. He can guide you in the right direction.
 

danbrennan

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Mar 13, 1999
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Brighton, MI
Damon said:
Weiand Street Warrior line. It's lower than the Performer or Performer EPS.

It is NOT as low as stock (nothing is as low as the stock "pancake" QJet intake), but everything should still fit.

Didn't find one with spread bore mounting :(

Apparently the intake GM offers with their ZZ383 doesn't clear a 1981 stock hood, from a comment I found on the internet. And I want to use the original air cleaner, with the fresh air duct from the radiator cover.

I didn't realize until now the vortec heads raised the intake manifold mounting height. Although I suppose that in part explains the additional horsepower.

http://www.summitracing.com/parts/nal-12366573/reviews

"This is the perfect intake manifold for a GM ZZ383 crate engine. The intake ports on the ZZ383 GM Fastburn Heads are very large and all the aftermarket manifolds I tried would not cover the ports. This manifold fit beautifully! Being a dual plane design makes this manifold work great through the entire rpm range of the engine. Hood clearance was still an issue on my 81 Z28 Camaro forcing me to replace stock hood for a raised cowl induction hood."
 
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Damon

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Nov 16, 2000
12,939
Philly area
If you're running a QJet and don't want a "Performer RPM-height" manifold, your only choice is the base model Performer for Vortec (#2116).
 

danbrennan

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Mar 13, 1999
4,963
Brighton, MI
And convert my Q-jet to electric choke :) But I don't think that will bother me too much.

I did gain some hood clearance when I had my Z apart for painting, by cutting a hole in the hood under the fiberglass hood scoop. I think that got me another 0.5" of clearance, with the stock air cleaner top shape. I'll do some measuring, and see how it looks. The 8 inch height of the #2116 manifold seems about the same as the GM dual plane aluminum intake I have on there now(old L82 Corvette intake, I think), and the air cleaner fits okay with that. As soon as this stupid subzero weather gets out of here!
 

Todd80Z28

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Jun 11, 2002
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Northern VA
How about GM 12496820? Low-rise, EGR provision, spreadbore pattern, comes on the HT383. I suspect it is a copy of the 2116 (i.e. Edelbrock might be the OEM). Though with the pad height at (A) 3.87", (B) 5.28", that's still 1/2" taller than my 2101 at 3.5/4.6... and it BARELY fits under my stock hood. I am using a 1/4" thermo gasket carb to intake, so I could get 0.2" back there. But still...:)

Weiand 8121 comes in at 3.4/4.5, that ought to do it, but no spreadbore...
 
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danbrennan

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Mar 13, 1999
4,963
Brighton, MI
"How about GM 12496820?"

Yes, that's the one I would substitute for the single plane manifold that comes with the ZZ383, so I can use my Q-jet. But I have a hunch it's not any lower than 12366573, the square bore GM Performance Vortec manifold, and that guy's comment above at the Summit site said that didn't fit under the hood of his '81Z. I'm not using a thick carb gasket, so I save a bit there.
 




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