Kim also completely reworked...
Kim also completely reworked the interior and dash, incorporating power windows and air conditioning into his ride, along with a tach, pyrometer and boost gauge so that he can monitor the 12-valve while he's on the road.
Of course, after Kim had completed all of this work, he couldn't just leave things stock. The engine was upgraded with a set of Stage 3 Diesel Dynamics injectors, a 3,000-rpm governor spring kit, an aftermarket fuel plate, 60-pound exhaust springs, and a timing advance. The result was about 100 horsepower more than stock, while also maintaining great maneuverability for hauling and towing. When we saw the truck at the J&H event in Redding, California, it broke during the sled pulling event. The 10-spline input shaft to the NP205 transfer case gave way, and prompted Kim to perform another series of upgrades. A 32-spline shaft was then installed, along with a South Bend 3250 dual disc clutch, and the input shaft to the NV4500 was upgraded from 11/4 inches to 1 3/8 of an inch.
But the drivetrain is where the modifications stop, right? Nope, not even close. Kim put a 21/2 inch lift on the front to help balance out the weight of the diesel engine, and built his own custom springs for the rear. One of his favorite additions is a set of in-cab adjustable Rancho RS9000 shocks that allow the truck to be supported when loaded, but aren't so stiffly sprung that they beat him to death on the highway.
What's really amazing, though, is the little stuff. Kim's influence can be seen on every single part of this truck. He and his dad custom-made the dump bed and rear bumper, and Kim even welded up a set of custom front wheels so he could have the proper backspacing, and still fit 33x12.50x16.5 tires. He put in power windows, remote entry, and air conditioning when the truck was restored. Almost every part on this GMC truck was modified in some way by its owner.
 Since some of his work sends...  Since some of his work sends him out of town, Kim whipped up a custom 50-gallon fuel tank to give the truck an extended range. The GMC/Cummins combo gets about 18 mpg on the open road, which means he has a highway range of about 900 miles between fill-ups! |  During his work, the GMC may...  During his work, the GMC may be required to lug up to 3 tons of rocks, gravel or sand, so the rear suspension has to be up to the task. Kim had a custom set of springs made for the 3500 to ensure it could handle the load no matter the weight. The larger tires are mounted as a result of a set of owner-made 11/2 inch wheel spacers. |  The exhaust system incorporates...  The exhaust system incorporates an exhaust brake and is actually made for a Dodge application. With a little "here-and-there" bending and tweaking, Kim got it to work on the GMC. |