piston to valve contact?

[john h]

I am going to be doing the head gasket on my 04 sentra in a few weeks, and while the head was off i was thinking of having 20 thousandths taken off to bump the compression a bit. is there any way i can find out if i will run into piston valve contact with out putting the putty shit on the piston and measuring it, the head is a pain in the ass on this car so i am trying to avoid doing it twice.

[zinister]

Keep milling it as much as you can. When the piston hits the valve, your too close. You will then have to trim the valve stem. lol

Honestly, The putty will probably be the best bet.