MOre info...First, Mark - I do intend to use this in Masters in 2005. At least I'll find out if there is a size prejudice!!!

Now - IF you are considering the ST 2300.... here are some things you must know.
1. Reduce the flange widths front to back. Pics earlier.
2. Stock mount works just fine. Even at idle, there isn't too much movement, it definitely isn't too soft.
3. If you use the stock muffler, you will need a 3/16" minimum spacer between the exhaust port and the muffler flange to permit the muffler body to clear the fuse side.
4. 16" props will work if you have a paved, smooth surface but NOT MUCH clearance if using stock wheels. 17" will NOT work. Suggest using larger wheels, or getting longer gear.
5. Balance - as predicted, with the stock ST and it's muffler hanging up front, I had to move the battery to 12" in front of the rudder hinge line, and add 2.5oz at the middle of the stab on the fuse. This gives 7.25" CG, with empty tank.

I'll do some pics later, but it really looks like it's supposed to be in there, guys. I was sure surprised.