Author Topic: Production or over the counter heads?  (Read 1936 times)

mopar346

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Production or over the counter heads?
« on: November 19, 2010, 01:19:15 AM »
I just picked up a set of 3991492 heads, were these production pieces or over the counter units? If production, what did they come on?

Ed B

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Re: Production or over the counter heads?
« Reply #1 on: November 19, 2010, 01:54:10 AM »
Over the counter / service replacements only.

Ed

mopar346

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Re: Production or over the counter heads?
« Reply #2 on: November 19, 2010, 01:59:57 AM »
Thank you!

mopar346

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Re: Production or over the counter heads?
« Reply #3 on: November 20, 2010, 02:04:03 PM »
Is there anything special about these heads over the production 2.02 heads? Different runner configuration or something?

JohnZ

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Re: Production or over the counter heads?
« Reply #4 on: November 20, 2010, 04:15:38 PM »
Is there anything special about these heads over the production 2.02 heads? Different runner configuration or something?

Angled plugs - never used in production.
'69 Z/28
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william

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Re: Production or over the counter heads?
« Reply #5 on: November 20, 2010, 06:34:55 PM »
Smokey Yunick mentions developing the head in the late 60's. When static compression gets much over 11.0:1 the standard plug location can become drenched with fuel. So Smokey would plug it and re-machine an angled mouting to move the plug. After several years he finally convinced Chevrolet to do it. I believe the '492' head did not have a passage for manifold heat. My 1975 Chevy Power manual mentions the machining of the casting was changed in 1972 to accomodate larger valve springs.

As with many of his ideas, someone else got the credit.

mopar346

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Re: Production or over the counter heads?
« Reply #6 on: November 20, 2010, 11:46:31 PM »
They are not angle plug heads. I had them shipped home Friday so I will double check the number when they get here but I am sure of the number.

KurtS

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Re: Production or over the counter heads?
« Reply #7 on: November 21, 2010, 11:57:46 PM »
I was gonna post that not all 492's are angled. I've never watched the dates, but some are straight. Wonder if they were a different part #?
Kurt S
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mopar346

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Re: Production or over the counter heads?
« Reply #8 on: November 22, 2010, 12:03:36 AM »
Don't know but when I get them in hand I will get you any numbers you want/need.