Drill the cylinders' skirts today

With the oil returning from the heads to the case via hose instead of the passage in the cylinder, I chose to put the fittings in the thickest part of the case, which meant that the cylinders' skirts would have blocked them off. To fix this, I placed each cylinder on the case, and using the fitting hole, used a center punch to mark the skirt where it needed to be drilled.

After marking, I used a 1/8" bit to drill a pilot hole, then chucked up a 3/8" to drill the final hole.