I know you stated Indianapolis area...but if you don't find anyone down there...I used a shop up here in Fort Wayne. The selling point for me was the father in law of the owner of the shop does work there and the father in law worked at the local Dana factory for 40 years...so I figured I would stipulate that this guy work on my truck and I had some pretty good experience working on my axles!
Anyway...if you don't find anything down there...let me know and I'll give you the shop name and you can ask specifically IF the father in law will be working on your truck...after all...why else would you be willing to drive 2 hours up to Fort Wayne for a gear swap!
If I may ask...what gears are you going to and what tires will you have?...do you plan on towing with the truck and also what engine do you have?...I ask all these questions because I'm into towing and I've seen too many people put large tires on their trucks only to have the wrong gearing in the axles...the truck is then a dog...
Also...If you are so inclined to stay in touch with the Indiana chapter...joining our chapter is painless, quick and FREE...simply click on the "Join Chapter" link at the top left side of this page! Once you join the chapter you will get any 'member' PM's that I send out...also subscribing to this forum gives you notifications of new posts in here when they happen...
My suggestion is to get some inputs from folks over in the 6.0 forum on gearing for towing loads similar to what you plan to tow.
From what I have heard unless you plan to tow really really heavy (like 14,000+ # loads)...your 3.73's should do you just fine behind the 6.0 especially with your stock tires.
I'm not completely sure where the sweet spot is on the 6.0 so that's why I suggest asking some folks that have that motor. Also ask WHAT they are towing weight wise to make sure your application is similar to theirs.
I'd hate to see you spend ~$750 on a gear change only to find out you really didn't need it...have you towed with your truck yet through any areas that give you concern and that is why you want to change?...I'm just curious.