Thanks Gary...I'll use the 4-40 hardware.

WW...I don't know about CG, but...the kit is rated up to 70 4C. Since GP usually rates their kits with OS engines, I compared the OS FS70-II with the YS63FZ. The OS70 weighs 20.3 w/muffler. The YS63 weighs 17.9. It still might be a little nose heavy, but you should be able to deal with it by just moving battery and receiver.

Maybe there's someone out there who's built it and would comment.