Ultimate K10, Part 1
Ultimate K10, Part 2
Ultimate K10, Part 3
Ultimate K10, Part 4
Imagine owning the ultimate 4x4. It would be able to handle any off-road trail in the world, drive from New York to Los Angeles in comfort, require almost no maintenance, and be something you could actually afford to build! If you're a regular reader of 4-Wheel & Off-Road magazine you've seen us construct a Super Duty on 46-inch tires, an Avalanche with four-wheel steering, and a fully fabricated solid-axle Tacoma. All of those trucks were unique, all of them were capable ... but all of them would have required winning the lottery to build! So rather than try to outspend ourselves on this year's Ultimate Adventure truck, we decided to take it in a different direction. This year we're going to build a 4x4 that will be "Ultimate" in every way--except for the price. We can't promise this year's truck will be cheap, but we'll do everything we can to control costs. Any exotic hardware that can't earn its keep will get left on the parts counter.
For starters, we're going to save money by avoiding the car payment and begin with a truck that's 30 years old. We picked up this '75 Chevrolet K10 stepside for $1,500 from GM Truck Center in Burbank, California. We got it 'cause it's rust-free and smog exempt, but the truth is our buildup plans will work for any '73-'91 solid-axle GM truck, and with a little imagination you could adapt it to a '72-'93 Dodge, or even a '73-'79 Ford.
 It's not pretty, but if the...  It's not pretty, but if the original small-block was in better shape, we would have ordered a Howell universal throttle-body fuel-injection kit and been done. Even with headers and an aftermarket intake, the 350 just didn't feel strong enough to move the 39-inch tires we plan to run. We knew that we needed 300-400 hp and that we should stay with the small-block for weight and cost savings. We also knew we needed fuel injection to handle steep off-road climbs. After sifting through all the options and searching for the best deals, we ended up choosing a Ram Jet 350 from GM Performance Parts. Rated at 350 hp and 400 lb-ft of torque with multiport fuel injection, the Ram Jet 350 is a steal at $4,900. It'll also bolt right in, work with the stock radiator, and ensure we'll be able to find replacement parts anywhere. |  We know some of you are digging...  We know some of you are digging the California snowmoflage, but the rest of you don't have to lose any sleep over it 'cause it's history as soon as KC Customs lays down the new paint job. The '72 grille, hood, and gas tank that were being stored in the bed will be evicted to make room for a fuel tank, 39-inch Krawler spare, auxiliary battery, air compressor, and rear-mounted Warn winch. It's going to be tight but we'll find a way to fit it all. |  Before you go thinking we've...  Before you go thinking we've started with a flawless 4x4, check out this mysterious frame repair. We expect every solid-axle GM truck to have cracks in the frame around the steering box, but our truck had a steel plate welded in on the passenger side near the bumpstop mount. Odd. The technicians at GM Truck Center think a busted engine mount could have let the small-block bounce around and crack the frame. Who knows? Hopefully this is the only Gremlin that our truck has. |
Our secret to keeping costs down will be to save as much of the stock truck as we can. If there's a part on our K10 that works and does what we need, it stays. Rebuilding old components is usually cheaper than swapping in new assemblies anyway. When we use brand-new parts, we'll prove to you why it was the right thing to do. We can already guarantee this Chevy will run more used and rebuilt stuff than all the other Ultimate Adventure trucks combined.
Our initial testdrive told us the truck was pretty solid, but the engine is tired and the transmission fluid looked a little dark. The good news is that even though the truck has had quite a few owners, it hasn't been too butchered. We're a little concerned about why the dash was half torn apart, where the front driveshaft went, and what kind of front-end damage caused the grille to disappear--but we'll get over it. We don't care what shape stuff like the axles and suspension are in because we know they're getting replaced with heavy-duty parts. For the same reason we're not too concerned by the windshield tag that says, "Next oil change in 3,000 miles or by 3/22/97."
 Backing up our new Ram Jet...  Backing up our new Ram Jet 350 will be a reworked Turbo Hydramatic 350 from TCI. We could have put any transmission in the truck, but the TH350 has a lower First gear than the TH400 (2.52:1 vs. 2.48:1) and is shorter than both the TH400 and TH700R4. With a decent rebuild, the TH350 should be up to handling 400 lb-ft of torque and 39-inch tires, but just to be sure we'll run 5.13 axle gears to take some of the strain off the transmission. With those gears and tires we'll be spinning the engine 2,872 rpm at 65 mph, which isn't high enough for us to justify the cost and complexity of going to an overdrive transmission. |  Nobody loves the NP203 fulltime...  Nobody loves the NP203 fulltime chaindrive transfer case. It's longer and heavier than the NP205 and has a reputation for stretching chains. We've never had a problem with an NP203 and would have kept it if we didn't need more low-range gearing. So we'll do the next best thing and convert it into an auxiliary low-range box with an Off Road Design Doubler kit. Instead of bolting an NP205 behind the Doubler, we want to run a chaindriven NV271 from a Ford Super Duty. It'll give us more gearing options--thanks to its 2.72:1 low range (NP205s are only 1.96:1) - and we're willing to bet it's as strong, if not stronger, than the legendary NP205. |  If we're wrong, you'll hear...  If we're wrong, you'll hear about it. We could sink a couple grand into fitting the interior with a pair of bucket seats and a set of aftermarket gauges, but that wouldn't fit the theme of this truck. Instead we'll focus on getting the stock gauges to work with the new Ram Jet, have the bench seat recovered, and restore the dash and weatherstripping to like-new condition with parts from the J.C. Whitney catalog. Now we've just got to figure out a way to fit a rollbar in this thing to meet the requirements for Ultimate Adventure. |
In this installment we'll let you in on some of our plans for our Ultimate K10. In Part II the guys at GM Truck Center are going to strip the truck down and prep it for a new Tuff Country suspension. We're going to keep the Chevy riding on the proven leaf-sprung suspension, but they'll be a few twists that will make it worth reading about. And we promise, it'll all be stuff that you can afford to do too.
Ultimate K10, Part 1
Ultimate K10, Part 2
Ultimate K10, Part 3
Ultimate K10, Part 4