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Rockcrawling in a Classic 1977 Chevy K10 Isn’t Easy, But That Doesn’t Stop Grant Chapman

Posted in Features on August 31, 2018
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Rockcrawling is a complex pastime. At one end of the spectrum you have JK Wranglers with 40-inch tires and coilovers that aren’t used for anything more than going to the mall and picking up the kids from soccer practice. At the other end you have Toyota pickups that have been rolled so many times they look like a crushed beer can. But most 4x4s fall somewhere in the middle of the spectrum, including Grant Chapman and his 1977 Chevy K10. Grant understands that sheetmetal limits where he can take his fullsize truck, but he willingly runs such trails as the Rubicon. Grant wants to keep his truck looking good, but if he happens to get a dent he understands it’s not the end of the world.

We can’t say we blame him, as this classic stepside is beautiful. The looks aren’t just skin-deep either. The truck features a stroker engine, an NV4500 transmission, an Offroad Design Doubler, and locked 1-ton axles. Grant doesn’t own a tow rig or a trailer, but living in Reno, Nevada, means that trails like the Rubicon aren’t too far away, and the Chevy goes down the road quite well. Grant admits that the truck was a basket case when he purchased it five years ago, but as he has upgraded and replaced parts it is nearly perfect. Let’s hope it stays that way.

Grant Chapman built the front bumper himself, starting with an A-Bomb centersection from DIY4x. The bumper is fitted with a Warn M8000 that Grant bought for cheap off of Craigslist and rebuilt.
The front axle is a kingpin Dana 60 filled with 5.13 gears and an ARB Air Locker behind the RuffStuff Specialties diff cover. Stock axleshafts transfer power to Warn Premium hubs. The WFO steering arms place the tie rod behind the center of the axle and above the leaf springs where it is safe from harm.
The front suspension uses DIY4x spring hangers to run 52-inch leaf springs that were originally on the rear of the truck. These longer springs provide an improved ride, and also increased articulation when combined with the 11-inch-travel Bilstein 5150 monotube shocks.
The rear axle is a 14-bolt that Grant shaved to match the Crane differential cover. The axle is filled with 5.13 gears and a Detroit Locker. Outside, the heavy drum brakes were replaced with discs using brackets from RuffStuff Specialties. The axle is hung under 56-inch leaf springs with the shackles flipped to provide more lift.
The interior of the truck is still relatively stock but pretty clean for a 40-year-old truck. Grant’s most recent upgrade was the DIY4x tube doors, which he says make a huge improvement in visibility. His next upgrade is to replace the factory bench seat with suspension seats.
When the factory 350 engine gave up, Grant stroked it out to 383 ci. He added a Summit Racing Equipment camshaft, Vortec cylinder heads, and throttle-body fuel injection for a big bump in power without breaking the bank. The engine is backed by an NV4500 five-speed manual transmission and an Offroad Design Doubler mating NP203 and NP205 transfer cases.

Tech Specs

1977 Chevy K10
Engine: 383ci Chevy V-8
Transmission: NV4500
Transfer Case: Offroad Design Doubler 203/205
Front Axle: Dana 60 with 5.13 gears and ARB Air Locker
Rear Axle: Corporate 14-bolt with 5.13 gears and Detroit Locker
Springs & Such: 52-inch Chevy leaf springs and Bilstein shocks (front); 56-inch Chevy leaf springs and Bilstein shocks (rear)
Tires & Wheels: 38.5x13.50R17 Goodyear MT/R on 17x9 Battleborn Gatekeeper beadlock
Steering: Hydraulic assist with PSC steering box, hydraulic ram, and pump; WFO high steer arms; Off Road Design tie rod and drag link
Lighting: SMD Halo LED headlights, GCD LED taillights
Other Stuff: York air compressor, DIY4x front bumper, Warn M8000 winch, custom rock sliders and gas tank skidplate, DIY4x tube doors, junkyard throttle body fuel injection

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