For this project I opted to stiffen the WSN chassis with a 0.80 styrene plate with structural ribs added. The lower hull is now very stiff, with virtually no flex. The upper deck will come from a Trumpeter static T-34. And I'm upgrading the stock WSN gear boxes with Tank Toko metal gears and bushings. Ethan added these to his SU-122 with good success. You can see both my Su-85 and his SU-122 build at our website at www.desertarmor.com