I think 2" is an ideal compromise between ground clearance, CV angle, and drive shaft angle. I know for a fact you can reinstall the axle housing with 2" longer brackets and 3rd member already mounted and sealed. Anything more than 2" and things would get tight when trying to put the assembly back in. Plus the angle at the drive shaft would maybe be too steep if you drop more than 2". The stock crossmember needs to be dropped as well though. Check Ascinder's gallery for some good pics of his solution. I am going to fab up skid plate mounts and a skid plate some time instead of using the OEM crossmember. Sadly, I have been driving around without any crossmember in place since I did this!