I am completing a basement reno for a friend. The floor joists are engineered i-joists 2X3 with OSB. The only option for the ceiling in the basement is drywall ( the windows are too close to ceiling for suspended tiles) Anyhow, the center beam in the house is terrible. Along the teleposts, there are severe peaks ( up to 1 inch; peaks and valleys on a 40 foot run). The exterior walls are fine, only peaks and valleys along center beam. Without adjusting the telepost to level ( it would cause major issues with upstairs if different stresses are put on walls, I would imagine major cracks at the very least). is there an acceptable way to sister a 2X3 onto the side of the bottom plate of the I-joist to basically level the ceiling? I am worried that the small 2X3 will not handle the twist of addiing lumber to the side of it and the weight of the drywall on that. Thoughts?