I've always used bolts and hex nuts when mounting engines, both in the fiber filled and wooden mounts. I recently bought a Great Planes adjustable mount for a kit and it came with the machine screws.

My first inclination is to drill out and use bolts, but I was wondering if anyone had any opinions on bolts vs. screws, or drilling and tapping. It seems the machine screws will be the easiest and quickest, but I'm concerned about the security of the engine. I'm mounting an OS 46FX.

Thoughts?