How much to shave off the cylinder head.

Charrlie_S said
I still say Measure what you have then figure what you need to do to get 8.7-9.0 CR. After 9.0 tuning can be a PIA, if wanting to run 87-89 octane.
Don't just go milling willy/nilly.

I completely agree with Charrlie. Measure and calculate first, then machine it. I took .060 off my head and now wish I'd done another .030-.040 off the block. I wanted to run regular swill in it so shot for 8.5 SCR. I got 8.4 but wish I was closer to 9.0.