I have a 2003 c4500 I use as a service truck it weights in at 16000 just the truck it has 14' service body with auto crane, I some times will pull a step van behind it when I need to transfer one from one location to another weighting additonal 8400#. I have no problem with pulling or stopping this amount of weight as I don't have brake on the towed unit just the 4500. I have 98,000 miles on mine now drive about 31,000 per year have never had top put brakes on it yet, loads of power very happy be think of buying another one crew cab this time to tow are livestock trailers.
2003 CHEVY 4500 DURAMAX/ALLISON 14'
SERVICE CRANE BODY 16,500 LBS 14.5 MPG
1998 K3500 SRW CREW CAB TRANSPLANTED 6.5TD ELECTROINC INTO, HEATH COMPUTER, 40+HP INJECTORS, 4" EXHAUST, VACUUM ELEMTINATOR ON TURBO,UPGRADED COOLING WITH ALL GM PARTS,NO VACUUM PUMP, SST OIL COOLER LINES MADE LOCALY FRACTION OF THE COST, 3" TOURBO/BOOST GAUSGE ALL IN ONE, ADDED GEAR DRIVE GREAT HELP WITH STARTING TIME DOESN'T JUMP AROUND ANY MORE, INTERCOOLER 3" INLET AND OUTLET COOLER 12x24x4, ALSO ADDED MANDEL BENT CROSS OVER, HAD TRUCK REPAINTED AND OPUT ON ALUM FLAT BED