1.) Is there a muffler available that is quieter than the Bennett (B&B) Style for my g-45. The stock muffler that came with this engine is very wide & will be a tough fit in my cowl.

2.) Any suggestions for the best prop for the G-45?
I have a G-23 & the Graupner props work great on it.

3.) Are there any adverse effects from mounting the motor in a
45 degree offset from the upright position??

Any opinions would be appreciated.

I took the outer half off of the stock muffler and braized the seams and holes closed. Then I cut a hole in the bottom and braized on a piece of 3/4" pipe for the outlet. I ended up with a narrower muffler.

A 20x10 or 22x8 works well on that engine, depending on the type of plane.

You can mount the engine turned any way you want. The carb pumps and meters it's fuel in any position.

Jim