I'm using an OS.46 on my UltraStik. Things I've done on mine:

1. strengthened firewall on inside with fiberglass cloth.

2. replaced mount with a DaveBrown mount. I've seen other mounts from other fliers in our club break on a hard landing. Purpose of replacing it for me was to save weight.

3. I tossed out the rudder pushrod, and installed kevlar pull-pulls.

If you are installing a big 4-stroke, you may not be as interested as I in saving weight...