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1987 Chevy K20 Truck - Cam Of Logged

Posted in Project Vehicles on June 1, 2006 Comment (0)
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The formula for a good trail vehicle is often elusive and time-consuming. This is especially true when attempting to craft a highly capable off-highway machine from a heavy, cumbersome, fullsized pickup truck. It's kind of like trying to teach an elephant to dance Swan Lake. Of course, if you throw enough money at something, anything is possible, right?

One of the interesting things about this '87 Chevy K20, owned by Sean Williams of New Egypt, New Jersey, is that he didn't throw a lot of money at it, yet the end result is a vehicle that is as much at home on the trail as it is on the daily commute. Williams accomplished this feat through trial and error as well as through careful calculation. He may only be 22 years old, but his years of 'wheeling have taught him valuable lessons about what works and what doesn't. He integrated this knowledge into his Chevy, and the result is a rig that can tiptoe through the rough stuff.

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The weak stock 10-bolt front axle is long gone. It has been replaced by a Dana 60 axle that is far more capable of enduring the stresses created during hard 'wheeling and the large 44x18.5-16.5 Swamper TSL tires mounted on 12-inch-wide Mickey Thompson Classic II aluminum wheels. Williams fitted the axle with 5.13:1 gears and a Detroit Locker. Power is transferred to the axle via a 1-ton front driveshaft with 1350-series U-joints. Williams wanted a beefy and functional steering system, so he created crossover steering using a modified steering box, a Superlift 2-inch-drop pitman arm, a custom drag link, and an Off Road Design steering arm with 2-inch block. Also included in the list of steering upgrades is a homemade hydraulic-assist unit. The front suspension consists of Superlift 12-inch-lift leaf springs, ORD Offset 1-inch zero-rate add-a-leaves, Hill 4 Wheel Drive 1-inch lift shackles, and Superlift shocks. As in the rear, Williams removed two leaves from each spring pack to smooth the ride and improve flex.

Williams estimates that the 468ci V-8 engine generates 480 hp and 510 lb-ft of torque, which is more than enough to adequately propel the big Chevy. The engine project began as a bare 454ci block and heads that he purchased from a friend. He had the block bored 0.030 over and then he fitted it with gobs of performance components including forged Speed Pro pistons, a Holley camshaft, Manley Severe Duty stainless steel valves, Harland Sharp 1.7:1-ratio roller rockers, Summit 3/8-inch-diameter chromoly pushrods, and an Edelbrock Performer intake manifold. An Edelbrock 750cfm four-barrel carb controls the fuel/air mixture, and the exhaust gases are piped through Hooker headers, Flowmaster mufflers, and 2.25-inch-diameter exhaust pipes. Other engine components include a Mallory distributor, Jacobs Ultra Torquer coil, Holley plug wires, Jacobs Off Road ignition system, high-volume Moroso oil pump and 8-quart oil pan, 200-amp alternator, and a pair of Optima Red-Top batteries wired in parallel. Naturally, all of this horsepower and torque was also adequately hard on transmissions. As a matter of fact, Williams says after repeated off-highway floggings, he easily destroyed a Turbo 350 and a Turbo 400. At this point, he fixed the problem once and for all by swapping in a bulletproof SM465 four-speed manual transmission out of an old dump truck. He mounted the new trans to custom crossmembers made from 2-inch box tubing and he installed a Luk Pro Gold performance clutch to ensure proper flywheel grippage.

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An unwelcome result of removing two leaves from the rear Superlift spring packs was an abundance of wheelhop. The smooth ride and improved flex was worth it, though. Nonetheless, the problem had to be solved, so Williams fabbed a custom antiwrap bar to keep the axle planted. It's fabbed mostly from 1.75-inch tubing. One end bolts to the front and rear of the 14-bolt axle, and the other end bolts to a custom frame crossmember.

Owner: Sean Williams, New Egypt, New Jersey
Vehicle/Model: '87 Chevy K20
Estimated Value: $27,000

Type: 468ci V-8
Aspiration: Holley 750-cfm four-barrel carb, Edelbrock Performer intake, Hooker headers, 2.25-inch exhaust, Flowmaster mufflers
Output, hp/torque @ rpm (estimated): 480 @ 4,500/510 lb-ft @ 4,500

Transmission: SM465 four-speed manual
Transfer case: Divorced PTO-equipped NP205

Front: Superlift 12-inch leaf springs (with two leaves removed), ORD Offset 1-inch Zero Rate add-a-leaves, Hill 4 Wheel Drive 1-inch extended shackles, Superlift shocks
Rear: Superlift 8-inch leaf springs (with two leaves removed), 3-inch blocks, 4-inch shackle reversal, Superlift shocks, custom antiwrap bar

Front: Dana 60, custom hydraulic-assist crossover steering/Detroit Locker
Rear: GM 14-bolt/Detroit Locker
Ring and pinion: 5.13:1

Wheels: 16.5x12 Mickey Thompson Classic II
Tires: 44x18.50-16.5 Swamper TSL


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