Hey Tom...
Absolutely, in fact About a month ago I pulled the 61 2 stroke out and installed the saito .72. It isn't as much of a rocket ship with the .72 but will still hover and pull out very nicely. Still has unlimited vertical. Hover is maybe 2 to 3 clicks over half. The torque of the .72 is much nicer then the 61 2 stroke. Spinning the same 13-4w prop at about 10,500rpm. That is down just over 1000rpm from the .61, but you'd never know it. The .72 spins up much faster. I am having a lot of fun with the passion. It has really helped out my 3d down on the deck tremendously. I have no fear of getting low due to the fact that it is so stable, light and powered just right. Still can't knife edge this plane with out really working hard, due to roll and pitch coupling. I can't mix it out on my radio because the radio won't mix with 3 channels.
Good Luck Tom.
Al Renkel