I also have a Twist. Evo .46 as power. JR 537 servos all around. I have a small metal plate in under the fuel tank and a pair of nuts and bolts up front. Mine balances between 4 and 4.5 inches. Total added weight is a tad less than 6 ounces. Once I get used to the Twist,
bigger engine will go in and I will take out the weight. That is of course I don't crash the SOB first!!!!

Dave...