In order to get to my 8.1-8.2 DCR goal, it looks like I will need the shave my heads. Since pistons, deck height and head gasket is already determined. I could change the cam, but from a few I've run through the calc, it doesn't seem to affect it substantially enough to get the goal I have.

I have GM alum. heads #12363390, with 110cc chambers. As I've been told, also same castings as Edelbrock heads.

I need to reduce the chamber to 96cc. Is the safe to do on this head already with a small chamber? Any drawbacks to doing this? How would I find out how much to machine?

Thanks for the help,
Jeff

You want to take the heads from 110cc down to 96cc?? I am not even sure if angle milling will do that for you. That is pretty drastic. Sounds like something is mis-matched in there. You may need to go to a closed chamber head, but then you could have piston/head issues if your pistons are strictly for an open chambered head. Angle mill may be the only possibility. The you have intake fitment and header fitment to worry about. Wait for one of the resident machinists to chime in.

I'm running a flat top Keith Black piston #KB224. Smaller chamber should not be an issue with this piston. Here's what my numbers look like:

http://www.72chevelle.com/jeffk/DCR/dcr1.jpg
http://www.72chevelle.com/jeffk/DCR/dcr2.jpg
http://www.72chevelle.com/jeffk/DCR/dcr3.jpg

This is with a reduction in chamber size:

http://www.72chevelle.com/jeffk/DCR/dcra.jpg

Jeff,
I've never cut those heads that far but on a flat mill you are looking at 80+ thou which would put you into the intake seat,,, & on an angle mill you are looking at probably 125 thou which is probably doable but does cause a few problems on a finished head.
Depending on chamber it is about 005-.006/cc for flat milling & depending on angle about
.007-.009/cc