Can anyone tell me if there is any real difference between the 6301/6302 exhaust manifolds used on a 1965 396 corvette and the 0827/0828 exhaust manifolds used on the later 1966 427s? Is there any performance advantage with using the 427 manifolds? I have a 1965 396 corvette that I am restoring and numbers matching is not to important at this time.

 

I apologize for throwing this back to you, but I would recommend that you talk with Paragon Corvette Reproductions since they specialize in GM licensed reproduction exhaust manifolds like the one your's talking about.

The only thing that I can recall about the 427 C2/C3 exhaust manifolds were that the high performance models had 2 1/2" outlets. I don't think that the overall design changed that much from year to year.

Hope this helps.

 

Thanks, I will contact them and see what they say.

 

If anyone is interested, this is what I found out from Paragon Corvette Reproductions. I have copied the email thread below.

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From Sam, To Paragon Sales

Can you tell me if there is any real difference between the 6301/6302 exhaust manifolds used on a 1965 396 corvette and the 0827/0828 exhaust manifolds used on the later 1966 427s? Is there any performance advantage with using the 427 manifolds? I have a 1965 396 corvette that I am restoring and numbers matching is not to important at

Sam

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From Paragon Sales, To Sam

According to my technical staff, the outlet angle of the manifold varies slightly between the 396 versus the 427/454 manifolds. They all fit the heads the same, but are not interchangeable if using stock exhaust. If you are having a custom exhaust made, it could be bent to meet the manifold outlets as required. Also, there is a slight difference in the top of the casting which is only cosmetic and does not affect the performance or mounting.


Thank you,
Blaine

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From Sam, To Paragon Sales

Thank you very much. This helps.
On your web site the 396 manifolds are more expensive than the 427 ones. Is this because the 396 manifolds are not sold as much?
Sam

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From Paragon Sales, To Sam

It is because the 396 manifolds are not sold very often and we only produce a few sets at a time which is very expensive to do.


Thank you,
Blaine
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Thanks for sharing the info. Didn't know that the exhaust outlet angle was different for the 396 model.