1991 IFS Chevy Silverado Wheeling

About a year ago we had an epiphany: The '88-'98 Chevrolet and GMC 4x4 pickups were rapidly dropping in price and quickly becoming a viable option for a fullsize wheeling machine, except for one huge drawback-independent front suspension.

Many 4x4 experts, ourselves included, will tell you that independent suspension parts are weak, expensive, complicated, lacking in travel, and have no real articulation-basically all-around junk. But what about letting real-world wheeling be the final judge? We needed to prove or debunk these claims once and for all and decided to find one of those chastised Chevys, do some common aftermarket upgrades, and run it through the scientific research of serious trail abuse.

Of course, we can break anything if we try hard enough, so the next few issues of the magazine will be covering a gradual ramping up of mistreatment to try and find the weak links, analyze actual costs, and eventually calculate definitive pros and cons of an IFS wheeling machine. Plus, it gives us a chance to spend some time out of the office or shop and in the dirt on "business."

This month we'll introduce the clinical test subject, go over what we did to get it prepped for our trail research study, and voice some of our early concerns or praise about the 4x4 attributes we foresee becoming issues. Then we'll check back in the following months and tell you exactly what happened when we hit the dirt. Will it still be running and driving, or will parts be strewn across the California desert? Are we going to be eating our words, or did the test prove once and for all that IFS ain't where it's at? And finally, if the IFS does fail, what would we do to make it more trail-capable? Stay tuned.

1991 Ifs Chevy Silverado Drivers Side View

No one on staff had an IFS 4x4 in their stable that they were willing to thrash for the sake of research, so we headed to GM Truck Center in Burbank, California. This is the same outfit that helped build our Ultimate Adventure Chevy stepside in 2005, and they make a fine business of finding, fixing, and selling '70s and '80s GM trucks and Blazers. When we explained that we wanted an IFS truck for some off-road escapades, they turned us onto this '91 K-2500 Silverado. This land yacht came from the factory with a fuel-injected 454 big-block, 4L80E four-speed automatic, and a transfer case that is actually shifted with a lever-not a pushbutton. Unfortunately, we got it with nearly 200,000 miles on the ticker, thoroughly thrashed both inside and out, and the big-block in the bed half disassembled and full of rainwater. Other than the 13-foot-long wheelbase, it is a perfect platform for our testing and cost us less than we spend on coffee in a year.

The first step was to get our budget beater up and running. With a few phone calls, many trips to the local auto parts store, and a bleeding credit card we had a new long-block 454 (from Pace Performance center in Niles, Ohio), under the hood and running smooth. It was not as easy as it sounds, but we'll save the complete engine install debacle for next month.

With the truck running, we wanted to take it out wheeling in stock form, but ran into some other issues with a 15-year-old truck that had been sitting for nearly two years. The cracked stock-sized tires would barely hold air, most of the dash was torn up after multiple stereo and security systems passed through, the driver-side window was long ago smashed ($100), giving the cab months of rain and crud from being out in the weather, and after fewer than 30 miles, the transmission didn't want to shift out of second gear. While under the truck giving the tranny a well needed service and filter change ($60), we also found a driveshaft U-joint at the rear 14-bolt full-floating axle that was ready to grenade ($40). Our budget beater was getting expensive fast and we hadn't even modified it from stock yet.

1991 Ifs Chevy Silverado Tuff Country Suspension Kit

Rather than a frustrating trip of stock wheeling, we decided some upgrades would be needed to give this land barge a fighting chance off road, but at the same time we wanted to test the IFS to really see what it could or couldn't do. Rather than dive into some high-dollar custom one-off long-travel IFS setup, we installed a basic aftermarket lift kit and some 35-inch tires and changed the axle gears to keep the drivetrain happy. We went back to GM Truck Center and started tearing the front end apart. One thing we found was how quickly the costs of lifting an IFS truck added up. The Tuff Country 6-inch kit we installed has a retail price of $1,459.95 and requires about 12 hours of labor depending on the shape of the truck. With hourly shop rates ranging from $60 to $85 per hour, that can add up to about $900, depending on where you live.

In addition to labor and the suspension kit, you also need to determine if your stock components are in good shape. Many suspension kits require reusing some stock fasteners, and if the A-arm bushings, steering tie-rod ends, and knuckle ball joints are worn, more cost can be added. We replaced our lower A-arm bushings, upper and lower ball joints, three of the four tie-rod ends, and the pitman arm with new Moog components. Total cost: $560.
In addition to labor and the suspension kit, you also need to determine if your stock comp
Another issue with IFS is the front axle halfshafts. One of ours had a busted CV boot (right), and though the new boot is only $15, we chose to splurge and get a whole new halfshaft ($55) rather than chance some internal contamination and spend time wrestling the new boot on. Our truck is the heavy-duty eight-lug 3/4-ton so it uses the same shafts as the 1-ton.
Another issue with IFS is the front axle halfshafts. One of ours had a busted CV boot (rig
One unexpected obstacle and cost with our well-worn truck was that the crossmember the torsion bars attach to was actually torn through from some serious abuse by a former owner (as in getting it way off the ground abuse). We pounded the metal back together, added some reinforcement plate, and burned it tight with a Hobart MIG-welder.
One unexpected obstacle and cost with our well-worn truck was that the crossmember the tor

There are two major styles of IFS suspension kits on the market for '88-'98 Chevys: those that lower just the bottom A-arm and use a new taller knuckle, and those that lower both the upper and lower A-arms. The Tuff Country kit is the latter version and requires a torch or plasma cutter to remove the old bumpstops since they occupy the space on the frame where the upper A-arms will now attach (arrow).
There are two major styles of IFS suspension kits on the market for '88-'98 Chevys: those
The upper A-arm drop brackets are attached so that they effectively lower the whole front suspension. You will need to drill some holes through the frame and attach the brackets. Some folks weld these brackets directly to the frame, but we are going to wait and see if they move at all before we make that addition.
The upper A-arm drop brackets are attached so that they effectively lower the whole front
The upper A-arm is attached to the black powdercoated drop bracket, while the lower A-arm attaches to a powdercoated lower subframe that encases the front differential. The front differential is also lowered to keep the CV joints within an acceptable angle. We didn't initially get a front skidplate, but will definitely try to build one before we attempt any rockcrawling, as the aluminum diff and front steering are a bit exposed. The rear suspension uses a 3-inch lift block and an add-a-leaf to bring the bed up to height.
The upper A-arm is attached to the black powdercoated drop bracket, while the lower A-arm

Almost any truck is affected by going to larger tires, and our best advice is to complement those larger meats with some lower gearing. We found a set of 4.56 gears for our GM 9 1/4 front differential, and decided that the addition of an ARB selectable Air Locker would not only help the off-roadability of our truck by keeping both front tires turning when we need it to, but also would help test the idea that a front locker will break parts in an independent front end. To match the front, GM Truck Center replaced the stock 3.73 gears in the rear 14-bolt with some 4.56 gears, but we left the factory Gov-Loc alone at this point.
Almost any truck is affected by going to larger tires, and our best advice is to complemen
Once the truck was finished, we replaced the old baloney skins with some 315/75R16 Dick Cepek radial Fun Country IIs (35-inch). We kept the stock 16-inch steel rims for bash-ability and since they had the factory backspacing. If we had used a kit with a new knuckle we most likely would have needed new rims. We headed down the road to Tyerman's Wheel Alignment Service to get the truck dialed in. An average alignment is another $100, depending on your local shop, but an important consideration of your truck's performance. We will return after a few weeks of abuse to determine whether wheeling an IFS truck knocks it out of alignment quickly.
Once the truck was finished, we replaced the old baloney skins with some 315/75R16 Dick Ce
Finally, another $100 was spent to reroute the driver-side exhaust crossover to clear the front driveshaft. This is another one of those things that may not seem obvious at the start, but can add dreaded delays before getting to the trail. Note the two support brackets that help reinforce the lower subframe as well as the lowered torsion bars. We will tell you next month just how much they helped or hindered off-road performance.
Finally, another $100 was spent to reroute the driver-side exhaust crossover to clear the

SOURCES
Moog Contact: Michael Proud 26555 Northwestern Hwy. Southfield MI 48034	Hobart
Dick Cepek 3-30/-928-9092 www.dickcepek.com	Tuff Country Suspension www.tuffcountry.com
GM Truck Center www.gmtruckcenter.com	ARB 2-06/-264-1669 www.arbusa.com
Tyerman's Wheel Alignment Service	Pace Perf. Center www.pacetruck.com