440 aspen

I have 452s on a low comp 440. I don't have the money to do a piston swap so I was thinking about having the heads milled. How many thousandths would it take to raise compression half a point?

moe7404

i found one CR calculator. there are others. but this one is easy to use. ask around as to how much octane that will work with how much CR. https://www.rbracing-rsr.com/compstaticcalc.html ,,,,dont for get the Marvel Mystery Oil. 4 oz to 10 gal gas. my engine starts faster with it. been using it for 30 years.

Coronet 500

Cutting .0042" removes 1cc. Head is about 90ccs. Some have removed up to .080".

So, 80thou = 19ccs. 90 minus 19 = 71.

All of this can easily be searched out but buying a modify your Big Block book would be a good purchase.

Removing .010" from head requires .0123" from intake surface.

Did a quick calc. with thin gasket and this would raise compression 1 - 1.5 points.

Forgot to mention, this type of modification with a bigger than stock cam and pistons with no valve notches can get tight and careful clay assembly would be recommended.

RacerHog

I would wait till you could do the whole motor...
Sometimes other issues come up when you start cutting on these heads that much..