2000 GMC Z71 Rollcage and Bed Weld - The Ultimate Z71

Pull out your ear plugs, set down that grinder, and come take a peak at what we've been working on. Last month we introduced you to our well-used '00 GMC Z71 1/2-ton and began its transformation into the Ultimate sleeper rig-one that may look like a mall crawler, but performs like a world class off-roader. And it can't be the Ultimate Z71 without the Ultimate Adventure! You know the weeklong wheeling trip where we grab a bunch of wheeling enthusiasts like you and drive more than 1,000 miles on extreme trails and country roads, through multiple states, making it one of the most grueling and epic four-wheeling journeys that you will ever see.

With the expert build crew at Off Road Evolution, we broke out the Hobart welder and went to town getting the truck caged and the bed bobbed. We also shaped up a few other heavy metal items to convert this mild-mannered pickup into a trail-dominating machine. Since we are trying to keep the overall look of the truck close to stock, but still want a trail-friendly wheelbase, we decided to chop 12 inches from the front part of the bed rather than the rear (take a good look at the lead photo again). This will shorten our wheelbase to an estimated 135 inches, helping to keep the 1/2-ton's belly from getting caught up on too many obstacles. Well, time's a wasting, and if we want to get this rig done in time for a quick shakedown run before the official trip, we've got to get back to work! And for those of you that can't get enough of the Ultimate Z71, be sure to cruise over to our Web site at www.4wheeloffroad.com for exclusive build photos and blogs.

Though a 14-bolt with 4.56 gears and a Detroit Locker is a great find, one thing you need to be aware of is the carrier's thickness. Traditionally you want to match up the carrier to the proper ring gear, which is usually some variant of 4.10 and down and 4.56 and up, but there's always an exception to the rule and the 14-bolt is one of those outlaw axles. Due to the thick 4.56 carrier, when you swap gears to a numerically higher set such as our 5.13s, the ring gear makes contact with the pinion support. The solution? Simply find a 4.10 carrier and you're as good as gold.

We break out the laptop and go to the laser cutter for a little cutting-edge bracketry. We also begin laying out our suspension. The best part? All the brackets we make come with part numbers, so if you are thinking about making your own Ultimate Z71, you can!

A rollcage is always a great...        read full caption A rollcage is always a great safety addition no matter what type of wheeling you do. We wanted to keep as much interior room as possible in our '00 GMC extended cab, so we gutted everything from the headliner down to tuck as much of the 0.120-wall, 13/4-inch DOM tubing out of the way. Creating a precision fit is no simple task. To get the bends right, Mel Wade from Off Road Evolution created a tube template that allowed him to adjust the bars to the right length and sweep. Then using it as a guide, he built each section accordingly.	Though we still need to add...        read full caption Though we still need to add our tubing gussets, the interior portion of our cage is practically complete. Be sure to keep your eyes peeled for a future issue, when we tie in the interior cage to the frame and bed for added support and to prevent as much bed flex as possible.	Bobbing your truck's bed from...        read full caption Bobbing your truck's bed from either end is a relatively time-extensive project and requires a bit of sheetmetal know-how and patience. Before we made the first cut on our shortbed, we created a cross brace to prevent it from warping.
Whether you're using a cut-off...        read full caption Whether you're using a cut-off wheel, plasma cutter, or run-of-the-mill Sawzall, you'll need a steady hand to ensure that the bed lines are cut perfectly straight. You may find it helpful to tack on a guide to keep your cutting instrument on the right path.	Sheetmetal clamps allow us...        read full caption Sheetmetal clamps allow us to begin the delicate process of welding the bed back together. We found it best to spot-weld the bed in sections, constantly checking alignment and making certain the panels remained even and straight.	It definitely requires a double-take...        read full caption It definitely requires a double-take at first glance, but that massive 12-inch section was keeping us from achieving our goal of a 135-inch wheelbase while doing our best to keep the truck appearing stock. And don't worry, we've got a few tricks up our sleeves to deal with that massive lower overhang in the rear.
	The rear portion of the GMC...        read full caption The rear portion of the GMC 1/2-ton's C-channel frame was a little on the thin side, and with the type of abuse we have in store, we needed to give it some extra beef. Using cardboard templates we cut and welded 3/16-inch steel frame inserts to box in the rear portion of the frame to gain more strength and rigidity.	With bed mounts marked and...        read full caption With bed mounts marked and a little over a foot chopped off the rear of the frame, we started in on the new bed attachment points. Using a holesaw we made openings in the side of the frame to feed the bolts up through the opening for the bed, since the bolts run up into the bed versus drop down from the top.
Using a Hobart AirForce 625...        read full caption Using a Hobart AirForce 625 plasma cutter we said goodbye to the original perches and ditched the massive and heavy 14-bolt drum brakes. Why a 14-bolt? Strength, availability, and price-even after all these years it's possibly one of the best bang-for-your-buck axles.	If you can tighten a bolt...        read full caption If you can tighten a bolt you can put on Off Road Design's rear disc-brake conversion. Using calipers and rotors from a '73-'87 3/4-ton GM, we were able to not only lighten up our 14-bolt, but improve stopping off road. The discs are self cleaning so we won't have to worry about mud-packed drums ever again.	Our 14-bolt came right out...        read full caption Our 14-bolt came right out of the yard with a factory Detroit Locker. Designed to set in the carrier as opposed to a complete carrier replacement, it should have no problem turning our 30-spline full-float shafts.
Setting up our Superior 5.13...        read full caption Setting up our Superior 5.13 gears was a breeze as the 14-bolt uses pinion shims that are easily swapped out by unbolting the four-bolt yoke. Though the housing is quite large, there are ways to clearance the bottom. Be sure to check out next month's issue where we'll show you how.