Deck height change???????

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Nov 3, 2004 | 08:36 PM

scottie2hottie

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From: Honkytonkville

Deck height change???????

Is it true that later(72+) 460 blocks had a raised deck height over earlier blocks? If so, why do intakes and such fit ALL blocks....wouldn't there be a fitting problem somewhere?

Here's my source:
http://www.reincarnation-automotive....s-1-index.html

Thanks for any input!
Scott

Nov 3, 2004 | 08:45 PM

tmyers

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From: Everett, Wa

We are only talking .020 here. Not a big deal here unless you need to square up a block.

Nov 3, 2004 | 08:51 PM

scottie2hottie

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From: Honkytonkville

.020 makes that big of a difference in compression?
Scott

Nov 4, 2004 | 02:09 AM

tmyers

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It makes a little difference but I don't really know what you are getting at. The big difference in compression between the early and late is the heads, 75cc or so compared to 95cc.

Nov 4, 2004 | 05:40 PM

scottie2hottie

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From: Honkytonkville

Quote:

Originally Posted by tmyers

It makes a little difference but I don't really know what you are getting at

I am getting at that a DECK HEIGHT CHANGE 'SHOULD' create FITMENT ISSUES for the INTAKE MANIFOLD, among other things......After I typed that reply about compression ratio I remembered this was the same year for the start of open chamber heads. I undestand that the compression decreased with the open chamber heads, but i was really wondering about the fitting issues.
Scott

Nov 5, 2004 | 02:29 AM

monsterbaby

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From: iowa

if during a rebuild, you mill your heads .010, and deck your block .010 to clean up the surfaces (very standard practices) you change the affective deck hieght the same amount, and very, very few people ever think about doing anything with the intake, and have no problems, I have actually decked a block .025, and shaved .030 of the heads for a combined total of .055, and when I bolted the intake on to check the intake ports had less than a 32th of an inch missmatch, and the only problem I would have had was the cork or rubber end gaskets would have been really squished, but thats ok becuase I don't use them anyway.
So the short answer to your question is no, you won't find fitment problems unless you try, and use early heads with a FI intake or vs. and on a 460 the difference in deck hieght makes about .5 compression difference using the same heads
Oh, and one last thing there is actually 3 different decks hieghts, upto and including 1970=10.300, 71-78=10.315 79 on=10.320

Nov 5, 2004 | 03:39 PM

scottie2hottie

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From: Honkytonkville

That just seems a little goofy that they'd change the deck height for no apparent reason...and that seems like a pretty big drop in compression!
Scott