Fill the groove with JB weld and hand file flat. Get the head fixed. Use something other than Felpro. Run it. When I was burning up Felpro gaskets, I called them. They told me that their perma-torque and race gaskets both hold to a max of 12:1 compression. At the time, I changed over to the orange gaskets from Dvorjak racing out of Florida. Never had a problem again, until I started cracking 915 castings.