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Discussion Starter · #1 ·
I have a flat top 498 engine that I had planned on using closed chambered heads that should have had close to 10 to 1 compression. The engine builder cut into the water jackets on the exhaust valve seats on several cylinders. They were repaired with ceramic and I am nervous about using them.
I have another option. I have a nice set of 781 heads with big valves ready to go. I was thinking of milling the heads some and maybe running .017 head gasket shims to get the compression closer to 9 to 1. I talked to a local big name engine builder tonight and he said the 781 heads were the way to go because the epoxy heads could fail and the 781 heads breath alot better anyway.
Is there anyone out there that run flat top pistons with 781 or 049 heads?
Thanks:beers:
 

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With 498 cubes I doubt you'll notice the loss of compression. I personally think the 781 are a better option.
 

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I would sell both sets of heads. Then put the money towards a set of Brodix R/R. You wont ever have to look back.
 
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I'd use the closed chambered heads and I have a set of bare -206's out in the garage just for the next flat-top pistioned BB I get.

I think it is a wash as far as power made b/c the open chambered heads will suck some better, BUT the closed chambered heads allow for more compression before detonation kicks in. And the compression is where the power will come from.

As always, jmho..

pdq67

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