Aluminum Intake for Big Block C-2

[Brian T.]

Greetings:

I am working on a C-2 project car. I purchased a 454 big block (1973-1985) casting number 361959 to put in it. Has oval port heads. What aluminum intake can i put on this, and carb. Dont want any hood clearance problem. Also need to purchase big block hood for it any way.

Really use your help.

Cheers,
Brian Thomas

[Mark E.]

Re: Aluminum Intake for Big Block C-2

Greetings:

I am working on a C-2 project car. I purchased a 454 big block (1973-1985) casting number 361959 to put in it. Has oval port heads. What aluminum intake can i put on this, and carb. Dont want any hood clearance problem. Also need to purchase big block hood for it any way.

Really use your help.

Cheers,
Brian Thomas

Doesn't the 66-67 L36 use an aluminum intake? That's an oval port 427 that fits under the stock big block hood. I believe the 454 and 427 deck height is the same, so the comparison is fair.

The C3 L36 set-up should also work. C3 hood clearance is less than C2, plus these are also oval port big blocks. They use Q-Jets so this option would look less original, but probably perform better on the street.

If these OE intake/carb/cleaner set-ups are hard to find or expensive, maybe shop for an aftermarket set-up with the same height. There aren't any aftermarket solutions that fit under the C3 BB hood, but maybe there's something for C2. In any case, be sure to look at the total intake, carb. and cleaner height when analyzing hood clearance.

[Joe L.]

Re: Aluminum Intake for Big Block C-2

Doesn't the 66-67 L36 use an aluminum intake? That's an oval port 427 that fits under the stock big block hood. I believe the 454 and 427 deck height is the same, so the comparison is fair.

The C3 L36 set-up should also work. C3 hood clearance is less than C2, plus these are also oval port big blocks. They use Q-Jets so this option would look less original, but probably perform better on the street.

If these OE intake/carb/cleaner set-ups are hard to find or expensive, maybe shop for an aftermarket set-up with the same height. There aren't any aftermarket solutions that fit under the C3 BB hood, but maybe there's something for C2. In any case, be sure to look at the total intake, carb. and cleaner height when analyzing hood clearance.

Mark------


The 1966-67 L-36 used a cast iron manifold, not an aluminum manifold. The only 4 barrel, oval port GM aluminum manifolds were those used for 1968-69 L-36. These will fit under the hood of any C2 although I do not know if they require a C2 big block hood. I expect not, though.

The Edelbrock Torker II will also fit. However, this is a single plane manifold and I do not recommend such for street applications.

There may be other aftermarket aluminum manifolds that will fit a C2 big block. However, I could not say which, if any. Other than the above-referenced, there are no other 4 barrel, oval port, aluminum manifolds that will fit under a C3 big block hood.

[Mark E.]

Re: Aluminum Intake for Big Block C-2

Thanks for the correction, Joe. It's interesting the L-36 used an iron manifold with a square-bore Holley for 66-67, then an aluminum manifold with a spread-bore Q-Jet for 68-69. The somewhat analogous LS5 (an oval port big block) of 70-72 then went back to a cast iron manifold.

So from an OEM perspective, Brian's choices for an aluminum manifold are limited to the spread-bore 68-69 L-36. If cast iron is acceptable, then the 66-67 L-36 (square-bore Holley) or 70-72 LS5 (spread-bore Q-Jet) should also work.

[Brian T.]

Re: Aluminum Intake for Big Block C-2

Greetings:

Man you guys are smart. So looks like 68-69 aluminum intake and Q-jet is my option. What casting number intake would be best?

Cheers,
Brian

[Brian T.]

Re: Aluminum Intake for Big Block C-2

Also on the aftermarket option, do we know the height of the stock manifold? Some aftermarkets are 5.75" but say wont fit under hood of corvette. Not sure if they mean C-2 or C-3 or with the big block hood.

[Mark E.]

Re: Aluminum Intake for Big Block C-2

The 1969 L69 intake is 3947801. Dr. Google may help with 1968, and it might be the same.

[Mark E.]

Re: Aluminum Intake for Big Block C-2

Also on the aftermarket option, do we know the height of the stock manifold? Some aftermarkets are 5.75" but say wont fit under hood of corvette. Not sure if they mean C-2 or C-3 or with the big block hood.

I asked the same question for C3s a few months ago; here's the thread:

https://www.forums.ncrs.org/showthread.php?111493-Big-block-aluminum-intakes-with-stock-hood-clearance-for-C3s

Maybe someone else has experience with C2 big block hood clearance.

[Joe L.]

Re: Aluminum Intake for Big Block C-2

Greetings:

Man you guys are smart. So looks like 68-69 aluminum intake and Q-jet is my option. What casting number intake would be best?

Cheers,
Brian

Brian-------


There are only very minor differences between the 1968-69 L-36 manifolds. None of the differences would have any effect, whatsoever, on your selection. The casting numbers are:

3919849

3937793

3947801

All of the above were Corvette-only pieces and never used on other Chevrolet models. So, they're usually hard-to-find and expensive.

[Peter M.]

Re: Aluminum Intake for Big Block C-2

Hi Brian,
Since 65 L78 396 corvettes had high rise aluminum rec port intakes I don't think you would have any problem with an aftermarket intake like a Edelbrock performer as long as you use a big block hood. I would compare the dimensions to be sure, also use the GM style air cleaner. The base drops down over the carb rather than sitting up of the carb air horn like some aftermarket air cleaners.
Make sure you don't have the "peanut port" heads on your 454.
Kind Regards

[Brian T.]

Re: Aluminum Intake for Big Block C-2

Greetings Peter:

How do I know if I have peanut port heads? What do I do if I have them?

Cheers,
Brian

[Peter M.]

Re: Aluminum Intake for Big Block C-2

Hi Brian,
With the intake off you can measure the ports, but you should be able to tell visually. A search of the internet should provide photos for comparison. Do you know what year your engine is?
I don't know the exact year when they started to use the peanut port heads, I seem to recall it was about 1980, they are very restrictive flow wise.
Kind Regards

[Joe L.]

Re: Aluminum Intake for Big Block C-2

Hi Brian,
Since 65 L78 396 corvettes had high rise aluminum rec port intakes I don't think you would have any problem with an aftermarket intake like a Edelbrock performer as long as you use a big block hood. I would compare the dimensions to be sure, also use the GM style air cleaner. The base drops down over the carb rather than sitting up of the carb air horn like some aftermarket air cleaners.
Make sure you don't have the "peanut port" heads on your 454.
Kind Regards

Peter------

Yes, I think that many aftermarket intake manifolds, which are available in both oval and rectangular port would fit a C2 big block. However, as you mention, the use of a C2 big block hood and original style air cleaner is necessary.

[Joe L.]

Re: Aluminum Intake for Big Block C-2

Greetings Peter:

How do I know if I have peanut port heads? What do I do if I have them?

Cheers,
Brian

Brian------


Please let us know the casting number of the heads you have. I can tell you what the port configuration is based on this info.

[Brian T.]

Re: Aluminum Intake for Big Block C-2

Greetings:

The block is from 1975 or 76. The guy that did the motor work ported the heads. I believe the heads are 346236 casting but need to confirm. I am just looking for a street machine but the cam is a little hot for my liking but the engine was a great price. Do we know what the comparible height measurement is for the stock intake?

Cheers,
Brian