Changing Gear Ratio From 3.73 to 4.10 - Is this OK?

Is it ok to purchase a Silverado with a 3.73 and then upgrade the gears to 4.10?  We've had a hard time finding a used Silverado (2007 or 2008) with a 4.10 rear axle and a dealer just suggested upgrading the gears of a 3.73.  I'm not sure if that's possible or advisable.  Any input is appreciated.
 
Thanks,   Dave 

Its ok to switch gears, it can get pretty pricey, and you will probably have to get the speedo adjusted unless it doesn't bother you that it will be off. Why do you want 4:10 gears? for towing, burning tires, or just want them? It also more then likely cause you fuel milage to go down.

Just have your dealer order you what you want! I know they are under pressure to get rid of inventory but I had the same problem, everybody has trucks on the lots with 3:73 gears and you tell a salesman that you want 4:10's and they try to talk you into 3:73's! It only took a month for my new 08 to come in ordered with everything I wanted and without the stuff I didn't want. And by waiting an extra month they came out with more rebates so i even saved an extra 2250.00
 
Changing the gears will cost WAAAAY more than the 150.00 x in the box on the option sheet.

I found out upgrading a 3.73 to a 4.10 was very expensive, so we elected to keep looking for a 4.10.  A dealer was able to locate a 2007 4.10 for us for the price we wanted to pay.  We picked it up yesterday and love it.  Now I need to learn about installing running boards, but that will be a separate post.
 
Thanks,   Dave