A big dually

Hey everyone, I've tried looking everyone and can't get a definite anwser. Just bought a 2000 GMC 3500 dually with the 6.5 diesal, full 4 door cab, 8ft box. It needs a bunch of body work. I found parts truck, but I'm not sure if it will work It's a 2000 gmc 1500, 2dr regular cab, 8ft box, single wheel. Can I use the box and front doors from it on my 3500? (with putting my current dually flares to the box) Not as concerned but also curious if the front fenders, front and rear bumpers and interior (seats etc) will work? Thanks a tonn guys.