How much milled off heads to raise compression

Hi Brooks,

I would never go over 10 to 1 in a street motor for sure!
If its a race motor then you need forged pistons that are specific for Nitrous.
If not then the ring lands will be destroyed in a heartbeat!

Pump gas is not good for anything over 9.5 so be careful.
Low comp is not a disaster and small cams do work fine with NOS too.