Used the unibit to drill and enlarge four holes in each the four quadrants of a 2" circle, then snipped out the remainder. Uused a rotary rasp to clean up the edges, and then deburred and polished with ScotchBrite. Drilled the mounting fastener holes and temporarily hung the cabin heat baffle on the firewall. Need to remove, seal with appropriate materials and mount permanently (later).
During this task, I realized that the new engine has a 90 deg oil filter mount and the F/W recess is no longer required. Will probably obtain some SS and cover with a flat panel instead of the recess.
