Bob,

I never worry about this being an unflown combo, by the time I get most of my airplanes in the air, the combo hasn't been tried before either. I checked on the servo size, I found that the 8231's are the same size as my 8411 SA's.
The weight of the 2300 is actually less than the OS-120 w/pump that I was going to put in it.
I'm assuming that you have the tank in the stock position, is there room to move it to the CG?

Sorry for all of the questions, just pre-planning. In my mind I'm already flying this plane

Ken