I got a 1997 GMC Sierra Z71 Extended Cab, and I hate the IFS so I want to do a Solid axle swap, butI dont know anything about the axles, or the gearing. I found a company to make the custom axles, but I am not sure if I want to order a set of Dana 60's or Dana 44's. I dont know the differance, and I am also unsure about all the measurments I need, and what to do for suspension. I just plain out need help and if anyone out there has ever done this conversion to there truck and could answer some questions for me that would help out so much.  

www.offroadunlimited.com has a kit for swapping a solid axle into your p-up, but they aren't exactly cheap  

Choose your axles according to what size tires you plan to run and how you plan to drive it.  Driven hard, 35" tires will max out the strength of a D44.  If you plan bigger than 35" tires, then plan on a D60 up front.  If you go with the D44 up front then your current 10 bolt rear will be the choice.  If you go with the D60 up front then for less money go with a 14 bolt semi-floater (up to 38" tires) or a 14 bolt Full-floater (38.5" and larger tires) in the rear.  Yes there are proven cases of larger tires on those axles I listed, but the tire size for the axles I stated are to prevent breakage (and that is with alloy axle shafts).  As far as suspension and going about it, offroadunlimited.com will be a very good source.  

go to fourwheeler.com and in the search box type in
( four-wheel-drive conversions part one,and part two)
theres two articles on what and how much you need for the swap and they tell you how much $ it will take to do the job. pretty informative  

Those are good articles, and the ORU kit is pretty dang good too. And I also believe that Rock Krawler has a kit out now too, so there is plenty to chose from!

Be sure to keep us update on what you do!