Yup that doesn't look like a big problem.

Using the aforementioned cardboard technique cut a hole for the cylinder head.

Then cut a "U" shaped area for the Pitts muffler.

The "U" will not be very large and it will also help cool the engine.

To install the cowl you will start by looping the cutout hole over the cylinder head, then getting it past the prop bolt, and then in place.

You may also need a hole or two for the needle adjustments.