Milling 243 question
The car is a daily driver. I will be using stock gaskets as well.
as much as .030-.035 but that will affect your piston to valve clearance
particularly if you have a larger aftermarket cam. Also 243 heads off ls6
engines have lightweight hollow stem valves which are 0.6mm or 0.0236 "
inches longer and can affect your pushrod length. Know what you have
and measure things to get it right. (sweat the details)

