I have a sukhoi with a ZDZ80, look in the giant forum, and do a search, I had to add 1.5lbs of dead weight to get it to balance 1" behind the rear of the tube... I have smoke on it too.

FWIW, the 80 is good power, it will hover no problem...but if your at high elevation I think it would be margional, especailly in summer temps... If you can afford it put a 100 twin on it! Mine is getting a twin this year... .02