99 new Dually conversion GMC???

I have a 99 new body style short box sierra and have bought the hub adapters and wheels so far. I picked up a set of fiberglass rear dually fenders. But I think I want to pick up a used box instead and go to a 8 foot box. I would just go out and buy a dually but I have done a tonn of work to this truck so far so I hate to just get another one. What other things am I going to have to do? extend the frame longer driveshaft ?? Anything else you an think of? They never made a short box dually did they?

never made a short box dually in your body style,they did in the 88-98.. i would get aframe if you could and swap over you stuff onto that and have to extend a lil make it a lil easier but then again if ur baggin u could build your own frame

If you are just putting the 8' bed on it, all you should have to do it extend the frame rails around 2', have a 2-piece driveshaft made (you will need to install a carrier bearing and cb crossmember), extend some wires and extend some fuel lines and you should be back in business.

Thanks for the info. I think Im going to like this site. I just bought a box from a guy this morning. But wont be able to go get it until after thanksgiving. What is the reason for a 2 piece driveshaft? Could I extend the frame rails and just get a driveshaft from the bone yard for a regular length truck. Although It really should be bagged. Dont you think?

2 piece driveshaft bc it will be pretty lengthy, and just do a 2x4 rear clip on that thing and extend it that way

It should be 1.5' longer, as I think the short bed is 6.5'. Just get a driveshaft from the bone yard for a standard cab long bed. Shouldn't be 2 piece unless it is a ext. cab or crew cab.

wont the rearaxle be too wide for the dualy setup to fit inside the dually fenders?