i have a 2007 chevy 2500 hd single wheel pickup and i want to convert it to a dually, anyone know where i can buy the fenders and kit

There is already a thread on this a few under this one.

http://www.chromewheel.com/adaptors.htm

There are a few different fender kits out there too. Usually the only difference suspension wise is the overloads. Of course, doing the conversion won't up your GVCW, will make for a more stable and comfortable ride.

I've done this swap three times myself, although several years ago and on '78/'79 Ford SuperCabs. It is a pretty straightforward swap. Back then I just used the fenders off the newer duallies or the whole bed, and swapped out the whole rotor because it was a one-piece deal instead of having an adapter bolted to the SRW front rotor. If I got lucky I found the Dayton dual-piston calipers on the donor trucks and swapped those out too.

If I were to do the swap now, I would buy a "new" takeoff bed. You can get them for usually around 1500 bucks and you may find one that you don't even have to paint if you're patient. The bedsides on the newer trucks like yours are all fiberglass on the outside instead of having a bolt-on fender like my '97 GMC has. Dual steelie wheels are usually pretty cheap with the chrome and centers and you'll probably need the lug nuts too. Some lugnuts will work with the the dualie center caps and some won't. I've seen the late model dualie rears going for anywhere from 800-1800 bucks. The only other thing you would need would be the extensions for the front hubs and the most I've seen a set of those go for is 150 bucks. You can probably get by on less than 1000.00 for extra parts if you sell your bed and rear end to offset the costs. The most expensive item you'll have that's not really a more or less even trade will be a set of tires, but if your tires are in good shape you can even sell your wheels and tires and offset the majority of those costs as well. You may want to check the part numbers for both rear u-joints to see if they're the same. Saves being disappointed later when everything is done and you can't go anywhere until you get the right u-joint (they make some with different size crosses in them) or have a yoke changed out on your driveshaft...

With the newer computers and stuff you may have to watch and get the right rearend ratio or swap gearing in the dually rear for everything to work right, but the wider stance of a dually rear is more stable for sure. I don't know if there are any speed sensors or the like that may be different on those, and if you have 4WD you must match your gearing to the front end(in case you didn't already know).

You won't get any additional towing capacity with the conversion, but you definitely will have a truck that tows its rated capacity a lot better than it did. If you're picky about those ratings, it's worth it to weigh your truck now and then weigh it again after you do your conversion. However much more it weighs when you're done is how much less your rated towing capacity is going to be. Make sure you have the same amount of gas and junk in the truck both times so your weigh is accurate.

It's not that bad of a job to do and can be done in a day with a capable helper and access to good tools. Expect your gas mileage to suffer some due to the extra tires on the pavement and a less aerodynamic shape. Good luck.