Because the add front lets the axle spin all the time..More then 2inches will take the cv boots out and they will tear like mad..Even at two inches you can tear them pretty easy..The problem is the inner boot I think only has 4 ribs when it needs 5..They do make a 5 rib boot that is heavy duty but there kind of spendy..I took some polyurthane and lined the last rib with it and have had no more problems with c-v boots..To convert over from add you will need the front diff,,axles,and front hubs..Its sounds like more work then it is..
