First, keep in mind that a bias ply 33 will often be closer to 34, so they aren't the same even though they are marked the same. That being said, I used to run 30X9.5 Cooper LTs in front and 30x9.5 Cooper STTs in back. The LTs were quite worn and measured only 27" when on the Jeep and the STTs were pretty new and measured 29" when on the Jeep. This never caused any problems off-road, no drivetrain bind was ever noticed, and it shifted in and out of 4wd with no problems. Based on this you probably won't have any problems with the drivetrain.