I balanced my GP Ultimate with a GP CG machine. I put wood blocks under the back of the machine to tilt the upright rods forward so that they cleared the upper wing. I had to clamp the machine down to the work bench to keep it from falling.

When you balance it you should use the small level that came with the CG machine. Put it on the stabilizer and make sure it is level when supported at the recommended point. The Ultimate can be difficult to balance by eye.