I'm in need of some lower gears, mainly because of going turbo next year and something better than 2750 rpm at 70mph. I can get a complete 373 rear for 50 bucks. Question is would it be cheaper to have a shop put in the new gears in my existing rear or buy the rear, rebuild it myself and have the shop just swap the rear? I would just do the gears myself but it will be my daily driver and I don't have a garage to do it in this freezing weather.
Don't worry about pulling the axles, diff, ring gear,driveshaft, pinion, then shimming the pinion, setting the backlash, checking the contact, etc. You also might as well change the wheel bearings and rebuild your trac loc too while you have it apart. If you have access to a dial indicator and some knowledge on how to use one you can do it yourself, but it can be pretty complicated if you don't really know or understand the general concept. Also, seing how you don't really have a place to do it, you should probably just have a shop do the work. Labor for just the gears would probably be about $300.
3.27s would be your best bet, that is the most commonly used turbo gear.