If the suspension is taken from a complete vehicle, like on the LandRaider so it isn't piecemeal. The LandRaider has the complete axle and suspension from a Wagoneer. Leaf springs and all. The vehicle is stable as can be at speed. Even with 36's. But let's go back to your front end. Stiffer torsion bars are going to hold it steady, as opposed to allowing it to flex. If'n you were deeply concerned with flex, you would need to go back to stock torsion bars. Even then, you'll be limited. The stock cv is your limiting factor. Look at how skinny it is. Take a gander at a Toyota cv. Seems twice as wide.