One serious weakness with the Cleveland design when it comes to racing is the block doesn’t have very good oil control, but that can be fixed. Troutman started by installing oil restrictors in the No. 2 through 5 cam bores. This requires tapping the oil gallery and installing plugs drilled with 1⁄16-inch holes. The No. 1 bore is a little different which we’ll show you in the next photo.