How much to Shave Heads ?

[JEFFTATE]

I've got a brand new sbc GM crate engine pn 10067353.
I bought it for the core value because it was knocking when they cranked it. Someone accidentally dropped a screw down the intake and damaged #6 piston.
These engines only have 8.5:1 compression ratio.( dished pistons )
So I'm gonna' put a set of hypereutectic flat top pistons in it and bring the compression up a little.
I figure the flattops are good for about 9:1 compression.

I'm also gonna' have to have the heads shaved just a little because of some damage to the head surface.(They are 76cc chambers.)
My question is:
How much should I have the heads shaved to achieve 9.5:1 compression.

[Steevo]

Better that you learn to do it right. Run the calculations precisely and then have your machine shop determine depth based on your desired chamber volume in "cc's". Guessing is a mistake. After you have messed around with the calculator below, you might find that you can request a mill job that yields 9.8:1. No reason to round down to 9.5 if you are armed with precise information. And try not to have the heads angle milled. Flat mill them. Angle milling can mess up valvetrain geometry or intake manifold mounting. It should only be used in extreme cases. So be sure to specify "flat mill to XXcc".

Post answers to the various blank fields requested in the following link and we'll go thru it together. while you are at it, have them perform a bowl blend and competition valve job if you have the tin.

http://www.rosspistons.com/calculator.php

[JEFFTATE]

Thanks Steevo.

[ParkerRS]

Jeff,
Who is doing your machine work? If I'm not mistaken I think you told me you worked or lived around Acworth during the YOE. If so talk with Tommy Goza, he is in the old town of Acworth and is tops for machine work in the area. He can also help you calculate what you want and need to do. The only warning is that he really likes to talk so if you call or go by plan on it taking some time.

[JEFFTATE]

Greg Walker at Walker Custom Performance (ph 770-439-6075 )is doing my work.
He's done some excellent work for some people I know.
And he supports the cruise nights at Canton.
And he's interested in building a pro-touring car.

He knows all the right way to do things ; I was just trying to go to him with a little knowledge so I didn't look stupid.

I know Tommy Goza pretty well. He's a great guy with a great reputation. But I just wanted to give Greg a try.