Hi Doug, I am trying to work out, the ID of the heads on my cars. I have an R Series Valiant (the first Series in Australia) with a cast iron block that has special marked on the head, as far as I can check the head has never been off. I am the fourth owner of the car; it was stored for 15 years. The aluminum blocks were never sold in Australia, I have asked around and found several other cast iron blocks with either the world special or a star which I understand denotes the head is for an aluminum block. My theory is that during assembly there may have been a shortage of the correct heads and that there were heads for the aluminum blocks available and these were substituted for the correct heads. Could this have happened?
The second part of my question is in relation to my 1962 Dodge Lancer G.T. This car has the aluminum block but the markings on the head do not match any for the aluminum block that I can find. The numbers on the head are . 10.5 . Is this a head that was designed for the aluminum block?
Both motors are working just fine, it is just a puzzle I am trying to solve. I know if I ever need a head for the Lancer, I can take the head off the R Series.
Thanks in advance for any help you can provide. Syd Coomes

Hi Syd,

Nice questions. Doug does not get on here much any more. Probably we can help answer your questions. The Special or star heads were used on aluminum engines in the early 60s, and I bet you are correct that they were also used on iron engines if there was a temporary supply shortage for standard heads. My quite confident memory is that around 1964, Chrysler incorporated the casting/machining techniques used on the Special heads onto ALL Slant 6 heads. Thus, later heads can be safely used on aluminum engines, even if not marked Special. Personally, I would get ahold of a 68-up head with the later combustion chamber because those are very easy to identify without casting numbers, and they would have the updated casting/machining. At the moment, I have a recently built aluminum engine with a ~1968 head on it and everything works fine.

Also note that Ryan Covalt had some more modern MLS head gaskets made for the aluminum engine and I have one on my engine. I have not raced this engine yet, but have leaned on it fairly hard, and the gasket has held fine. I have 9.6:1 static comp ratio, and a 230 deg @0.050" cam in this engine.

All the best and hope this helps,

Lou

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Home of Slant6-powered fun machines

Hi Syd!
The "number" head you talked about was also an early head.
I have one of those as well.
I have all three, SPECIAL, Star and Number.
I don't see much if any difference in any of the combustion chambers.

I agree with Lou, you should be fine with the later heads on your aluminum block.

Good luck with your projects!

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Hyper_pak

The first round of aluminum blocks got heads marked "SPECIAL" instead of "2206035" on the pad just outside the valve cover rail on the manifold side of the head (2206035 inside the valve cover rail)

Second round: 5-pointed star in that location (2206035 inside the valve cover rail)

Third round: 2206035.

The thing to understand is that a head compatible with an aluminum block (closer control over combustion chamber placement, a bit more pushrod clearance) is also compatible with an iron block, but not the other way round. So starting in the middle of '62 production, the aluminum-block-compatible head was used on aluminum + iron engines alike. All with the same part number, 2206035.

The R- and S-model Valiants were assembled in Australia from CKD kits shipped from North America. Making CKD kits was a low volume kind of side project, as was the aluminum block, so it's not out of line to imagine aluminum-compatible heads making it into a CKD kit or two. It wouldn't have caused any problems.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I meant to post this with my response.
My "number" head.
Casting number under valve cover is 2206035.

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Hyper_pak

Can't help with that one!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thank you all for your input it is greatly appreciated and extremely helpful, you are a cyclopedia of knowledge.
Regards,

Syd Coomes

You are welcome.
More than you wanted to know probability.
Some of us are bored.

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Hyper_pak