These pics show my very late production head fitted on my very early production Aluminum Block. The voids in coverage of the deck surface give me more than a little pause! Anyone care to test this; not me!

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. . . there was good sport at his making.

I dunno....Don't use a later head with an early block?

*clickPOP*

Doctor Dodge, paging Doctor Dodge to the engine forum, stat...

*POPclick*

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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 just compared three head gaskets and found that the special "aluminum only" copper one covers the deck completely, the mid production standard one almost covers the deck and the late production one looks like the previous pics. Even though I'd be using the correct gasket (duh) it still seems that coolant would easily escape into the lifter galley. I had hoped to use this super late head with this super early aluminum block because of the "wacky factor!" I just like to have fun. But this doesn't look like the kind of "fun" I had in mind. I doubt that this would be a prob with any regular (sealed deck) iron block, but good to know for the Aluminum Block crowd. I would have missed this if DD hadn't pointed to the importance of matching the head to the block (thanks Doug!)

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. . . there was good sport at his making.

Bump!

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. . . there was good sport at his making.

I'm using a 1980 head on my 1963 aluminum block (with the correct head gasket). So far, so good at 4500 miles. Just make sure you go back and re-torque the head after you run the engine a while. I flogged mine one day and got some water in the oil. I checked head bolt torque and had to twist a quarter turn or more to get back to spec. Changed the oil, filter and antifreeze 2 times and cleaned the brown foam out of the valve cover and have been OK since. I've checked torque since and it is OK. I have a spare gasket, just in case.

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'63 Valiant V200 Convertible
225 Aluminum Block

Yeah, the aluminum-block head gasket is not a no-retorque design. It must be retorqued after installation and run-in.

I'm kind of surprised Doc hasn't commented in this thread... :shrug:

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

A busy couple of weeks in progress, work, home and racing... all "stacked" together.

Thanks for posting this, it seems to confirm what I suspected but honestly, have never 'mocked-up'.

Basically, the 81 and newer "wide valve cover" hydraulic lifter head will not seal the open deck of an aluminum block because the large (1 inch diameter) pushrod holes (lifter removal access holes) over-lap with the alm. block lifter gallery dividing wall.

I have tried 77 to 80 "small plug" heads and they do not have this issue seeing that the pushrod hole - thru holes in the head are smaller. So yes, you can use a "peanut plug" head, but not the 81 and up "wide valve cover" version.

As already noted, no matter what head you plan to use on an Alm. block SL6, you need to fit check the head to the empty cylinder block, to be sure that the combustion chambers are centered over the cylinders.
Also be sure there is not a lot of valve relief on the sides of the combustion chambers, these reliefs help air flow but tends to undermine the narrow head gasket sealing surface, at the tops of the alm block's bores.
DD