RE: Great Planes Reactor GP/EP 3D ARF .46-.70
Amyam
This thread has a lot of good info to help you on your decision. In this thread it was discussed that you can shoe horn a .91 in the front but you will have to add alot of weight to the tail and or move the battery to the tail. The plane is light enough to get away with it. One guy had a .91 and loved it. You have to make sure your .91 is one of the lighter ones preferably and if I remember correctly the guys in this thread stated that you want to keep the motor weight under 22 oz preferably. I think the newer saitos were in the weight limits and still had loads of power. I had a .46FX and it was nose heavy. Didn't like it. Changed over to electric and its much better!