i was wondering about how much money i would be looking at spending if i had 4.10 gears installed in my 9.75 rear end 2001 supercrew with parts and everything. Ball Park Figure, its 4x4 so i assume i need one for the front also

 

$1000 - 1200

 

Are you considering LS, or lockers? Now's the time if you're having a gear change done. I paid $2k to have both done, including the Eaton LS.

 

These pricws sound right and just as 1muddytruck said, now is the time to consider traction aids. if you dont upgrade now, you will wish you had. also remember that you will have to fix your speedo after install

 

I'm considering the same gear switch. What exactly does limited slip and lockers provide?

 

Limited slip helps keep both wheels turning under most situations, and requires no input from the driver. As its name implies, it does allow some slippage, which gives you acceptable on road cornering manners, with minimum tire chirping. It is a great choice when you want better traction on road as well as off road.

Lockers are just that - they completely lock the diff when engaged by the driver, and do not slip at all. They provide maximum traction off road, but are normally not used on road except in heavy snow. This is the mod of choice for serious off road trucks.