At all costs I try never to add weight to my models. I think I have had only had two out of all my planes where getting a good balance would not happen unless I added weight. I just dont get how the that plane would still be tail heavy if you had the servos in the stock location. The only thing extra I have on my plane is a perry pump which added like no weight at all. Let me know how it goes. At least when you fuel it up it will make it more nose heavy! Of course it will get tail heavy as you fly, so just be careful when you land