I have a 1991 ford f150 quad shock. I am looking into either a 4" or 6" lift from superlift. My big question is, will i need to lengthen the drive shafts if i go with a 6" lift? i know i wont have to with the 4" lift, but im not sure with the 6". Also from your experiances is superlift a good lift? I like superlift becuase they have both the longer radius arms, that are clearanced for the tires and becasue of there superunner steering. Any one have problems with superlift? Any thoughts or input would be appreciated.