Big-block aluminum intakes with stock hood clearance for C3s?

[Mark E.]

What oval-port, spread-bore, aluminum big-block intakes are available that will fit under the stock C3 hood (big-block hood for 68-72; cowl induction hood for 73-74)?

So far, the only one I know about is Chevy's L36 intake, which are expensive and hard to find in good shape. According to Edelbrock, Jegs and Summit (I called) there aren't any aftermarket solutions.

I'm asking for two reasons: I think an aluminum intake on my '70 LS5 would be cool, and I'm thinking about a project '73 using a ZZ454 crate engine, stock Q-jet, air cleaner and cowl induction set up.

Obviously, no points for originality with this, but with the original carb and air cleaner, it should look clean.

Thanks guys.

[Joe L.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

What oval-port, spread-bore, aluminum big-block intakes are available that will fit under the stock C3 hood (big-block hood for 68-72; cowl induction hood for 73-74)?

So far, the only one I know about is Chevy's L36 intake, which are expensive and hard to find in good shape. According to Edelbrock, Jegs and Summit (I called) there aren't any aftermarket solutions.

I'm asking for two reasons: I think an aluminum intake on my '70 LS5 would be cool, and I'm thinking about a project '73 using a ZZ454 crate engine, stock Q-jet, air cleaner and cowl induction set up.

Obviously, no points for originality with this, but with the original carb and air cleaner, it should look clean.

Thanks guys.

Mark-------


The ONLY aluminum, spread bore carb flange, oval port, big block manifolds that will fit under the 1968-72 big block hood are the 1968-69 Corvette L-36 manifolds. Period.

There is one aftermarket, aluminum, oval port manifold that will work but it has a square bore (Holley) flange. That manifold is the Edelbroack Torker II. However, this is a single plane manifold and I don't recommend it for street use.

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Thanks Joe; I appreciate the information.

With the myriad of aftermarket intakes out there for all kinds of applications, you would think some one would make one for big block Corvettes.

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Mark-------


The ONLY aluminum, spread bore carb flange, oval port, big block manifolds that will fit under the 1968-72 big block hood are the 1968-69 Corvette L-36 manifolds. Period.

Do you think a big block with an L-36 intake will fit under a 73/74 cowl induction hood with its stock Q-Jet and air cleaner installed?

[Joe L.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Do you think a big block with an L-36 intake will fit under a 73/74 cowl induction hood with its stock Q-Jet and air cleaner installed?

Mark-------


I expect it will but I can't say for sure. My expectation is based on the fact that the 68-69 L-36 manifolds and the 73-74 LS-4 manifolds have about the same profile.

[Edward B.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Mark, the old Holley Street Dominator has a measurement of 2" from the intake mounting to the top of the carburetor mounting flange. It should fit. You can't buy them new anymore, but they're available used for around $100. HERE'S ONE on Craigslist.

Ed

[Joe L.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Mark, the old Holley Street Dominator has a measurement of 2" from the intake mounting to the top of the carburetor mounting flange. It should fit. You can't buy them new anymore, but they're available used for around $100. HERE'S ONE on Craigslist.

Ed

Ed-------


This is a single plane manifold. I do not recommend these for the street. I used an Edlelbrock Streetmaster small block manifold once-upon-a-time. I didn't keep it on for very long. Just a miserable street manifold. GM never used a single plane manifold on a carbureted Chevrolet V-8 engine. They had it figured out long before I did.

However, the Holley manifold you referenced does have provisions for EGR which is necessary for stock 1973-74 Corvettes.

[Edward B.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Joe, it actually wasn't a bad intake! Ran well from idle to about 5k. Good throttle response too. I'd say it's comparable to the stock L36 intake. Just don't go hot rodding with it. You'll be disappointed! I had it on a 396 in the 68 Camaro for awhile. I had to have hood clearance and this one fit great.

Ed

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Thanks Edward.

It's hard to tell from the single photo, but the Dominator in your link looks a lot taller than the stock iron manifold on my LS5. I'll measure mine and see how it compares to the 2" dimension you mention.

When you say '2" from the intake mounting to the top of the carburetor mounting flange', how are you measuring that? Are you extending the plane of the sloped carb mounting flange to the front of the intake, and comparing that to the height of the intake/block interface? Or just measuring the vertical distance between the sloped carb mounting flange and the front intake/block interface? (I hope that was clear. )

[Edward B.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Here you go Mark. (A picture is worth a thousand words, right?)

Ed

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Thanks Ed. I'll measure and get back to you.

[Edward B.]

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Ed,

The dimension you reference is 1 3/8" on my stock LS5 iron manifold, which means the Dominator pictured is about 5/8" higher. Given how the air cleaner seal touches the hood already, I don't think that will work with the 73-74 cowl induction hood. I'll need to check clearance on the 68-72 BB hood, but I don't think there's much room to spare.

[Edward B.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

You got me curious, so I just went out and measured my stock 69 L36 intake height and it looks to be approx. 1-3/8" also. With the air cleaner installed and the hood shut, I have approx. 7/8" clearance (see pictures), so you might be able to get away with using the stock big block hood.

Note: Now that my grand daughter has moved away, I no longer have Play-Doh in the house, so I had to improvise! Yes, that's a stick of Imperial Margarine!!!

Ed

[Mark E.]

Re: Big-block aluminum intakes with stock hood clearance for C3s?

Ed,

How ingenious to use butter to measure hood clearance! And thanks for the data.

You confirm that the L-36 intake is the same height as the LS5 intake; good to know.

Using our numbers, if the Dominator was installed under a 68-72 BB hood, there would only be about 1/4" hood clearance. Maybe others can chime in, but that doesn't seem to leave much margin for engine tilt under load from motor mount slop. For comparison, if I remember correctly, AIM specs 1/2" or more clearance between the fan and shroud. This is probably to handle engine tilt as well, so this gives us an idea of what the hood clearance should be.