Are my heads interchangeable

[Brian 84]

I have a 1963 catalina 389 I also have a 1965 389 as well can the heads from the 1965 bolt up to my 1963 block . This would allow me to used after market intake manifold. Thanks

 

[omologato]

Yes they should be the same heads and interchangeable.

The head gasket part # is the same for both years which says the passages, bolt holes, cylinder bores, etc.......... are the same.

 

[Brian 84]

Ok just checking because the bolt holes on the 63 heads will not accept an aftermarket aluminum intake but the 65 heads will. Thanks for the reply

 

[omologato]

Ok just checking because the bolt holes on the 63 heads will not accept an aftermarket aluminum intake but the 65 heads will. Thanks for the reply

As long as everything is correct between head and block you should be fine. Do you have the engine codes for both years?

I'm not an expert with these engines specifically but I know there were lots of different little differences like intake and carb options. Id think the biggest thing in my opinion would be to make certain both engines are both high compression 389's or low compression 389's. Both had 2bbl and 4bbl so you can't tell by that. I think the only way to be certain is check the engine codes.

Double check if you have to bring the exhaust manifolds over with the donor heads.

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[Kraig1957]

I've made the conversion to newer heads on my 1964 Catalina. The heads I got were from a newer than 1965 Pontiac (1968 GTO 400 is what they said they were on) according to the auto recycling yard I got the parts from back in 1994. The rear of the head water passages to intake manifold are covered by the 1964 and older intake. The newer style heads 1965+ use an expansion plug on the driver side, and a heater core hose nipple on the passenger side. The hose nipple to heater core on my 64 was in the intake manifold water passage in front of the carburetor IIRC.