Reduction gears are $1250from marks adapters and 4.6s are $695 each end just for the crown and pinion then you will need an overhaul kit about $240 each end I 'twas going to do the install my self but if your out a little bit on measurements etc you could F it all up I'd pay an expert to do it. I bought my 35s, 4.6s overhaul kit and got it installed with a front locker everything done drive away cost $4800 it's not cheap to run 35s but now I know it's gonna be reliable