rear bag mount help.. anybody

[lotik]

the truck has stock trailing arm suspension, and i had the bags mounted over the axle, but the lift was pathetic. so i moved the bags onto the trailing arms. i mounted them off to the side on some plate. i have gussets on the mounts as well. but when i put air in the bags, and i push pown on the bed the trailing arm kind of twists a bit in the middle. i think it may actually be twisting in the front of the arm where the bushing is. but i can only see the middle where the mounts are. is this going to fail sooner or later, or will it be ok? i cant think of any other way to reinforce it. the bed as a 15gal fuel cell, air tank and compressor and two bottles of nitrogen. so that is the weight in the rear. please help. i really dont want to redo them, but i will if it will be unsafe.