are they a direct replacement? are all the controll arm, shock tabs and coil buckets in the same spot. If so then its not too bad at all, could probaly get it done in 8-10 hours. Is the yolk the same, is the new axle pinion longer/shorter if so you might have to shorten the drive shafts. E brakes cable brackets? basically if its ready to go then 8-10 hours for the average weekend warrior, or possibly 2 or 3 days if you need to do alot of modifications.