I tried something in my Ultra Stick 60 that was recommended by a club member. I put the rear of the tank right at the CG, so that when the tank does empty during flight little change in balance is seen. The only question that I had during construction was if the tank would be to far from the engine to pump the fuel without help. I have flown the plane approx. 10 times now and I can say it works great. However, in probably other planes the fuse may not allow it. I just had the room