The beauty of head milling

[RancheroBoy]

Alright, I got my larger 200 head. Magnifluxed it, and checked it for any changes that aren't stock and they aren't. So i'm trying to get it back to a modest 8.7 static compression. And every time i've put in my info on a calculator and I get something around 6.5? HELP! (P.S. gasket thickness is .044)

 

[Econoline]

Can't help without some info.

Has the motor been bored? How much?
62 cc chambers in head?
What's the deck height above pistons in block?
Piston dish volume?

Assuming virgin bore, 62cc chambers, 6.5cc dishes, .044" gasket and .020" deck height, I come up with 7.8:1

With those specs you need to get to 52cc chambers to get 8.76:1

52cc chambers would be a pretty safe bet, even if you were off on deck by .01 and it was bored a .02 you still wouldn't go over 9:1