6066 (1960-1966) GMC Truck Club

6066 (1960-1966) GMC Truck Club (https://6066gmcclub.com/index.php)

- GMC V6 and V12 Engines (https://6066gmcclub.com/forumdisplay.php?f=9)

- - Intake manifolds (https://6066gmcclub.com/showthread.php?t=51056)

Intake manifolds

Can anyone tell me the difference between the different intakes and are any of them interchangeable. Thanks, John

Re: Intake manifolds

A quote from BigBlockV6;

Quote:

Just remember that the V12 has different intake manifolds due to spacing and they will not interchange with the V6

(question asked)
That is an issue with the magnum heads. Correct?

No That is an issue regardless of heads You simply can't use V6 intake manifolds on the V12 nor can you use V12 intake manifolds on the V6.

Other than the above, my understanding is that they interchange.

I changed out my One barrel intake for a two barrel and did the Holley upgrade.

Now another member, TJ, put a magnum manifold onto his non-magnum 305, with a four barrel carb and it runs fine.

Re: Intake manifolds

It look like it will bolt up. But the port will be mismatch, see attached pictures.
I place both manifold upside down with the magnum on the bottom. With an old gasket on the manifolds you can see the different in the port size. The standard gasket will cover the full flange area of the magnum manifold.

Re: Intake manifolds

FWIW

There is a set of Fel-Pro MS90065 Magnum intake gaskets on ebay

https://www.ebay.com/itm/285260287413

Not mine

GL