Buggies have been quite controversial in the off-road world over the last decade or so. Their radical capabilities have been something to marvel at, but some wheelers complain about the lack of recognitionwith a real vehicle or the limited runtime, or the lack of creature comforts that a normal street-legal vehicle is adorned with. Rock buggies have definitely been making a niche for themselves, and it remains to be seen if they are holding on or dwindling in popularity. The fanfare of the "newest thing on the block" has died down, and now the future of off-road buggies relies upon their ability to adapt to what people's needs are, instead of the fad craze that had been selling more buggies than the actual utilitarian nature of them.
The typical rockcrawler buggy and its 10 minutes of runtime/fuel reserve has started to evolve into two different animals. One is so extreme that the resulting tubeworks are starting to look like mini monster trucks, while the other (probably the majority of buggy fans) is looking to put on bigger fuel cells for longer off-road trips, space to carry gear, functioning climate controls, and even street-legal tags so it doesn't have to be trailered everywhere. It seems that rock buggies as they were known are going the way of the dodo, and a new species of tube buggies quickly fills the void.
One such extreme example happens to come out of Calgary, Alberta, Canada, where we recently caught up with it and its owner/builder/creator Clayton Kraatz at the 2006 Alberta Safari Challenge. The sheer size of this monster almost towers over a 2 1/2-ton truck, and the build was straight out of the monster-truck instruction manual. It's a good thing Clayton keeps helmets handy in case he wants to get really rowdy.
That is a Rockwell F106 axle you're looking at. It's not the 2 1/2- or the 5-ton axle, but instead a commercial equipment axle that could be aka'ed a 3-ton version with 1 15/16-inch axleshafts. If you're going to get Rockwell axles, these are the ones to have, but they're harder to come by than the military versions. Detroit Lockers sit in both pumpkins with 7.17 ring-and-pinions geared around them. Keeping those 49-inch Iroks apart from each other is a full hydraulic setup using a custom 3-inch-bore balance ram with 3/4-inch rod ends on either side. And those big shocks? Those are Night Stalker monster truck shocks that give Clayton's big buggy 26 inches of front travel. The rest of the suspension is a four-link setup using Evolution joints and an antisway-bar setup that is built onto the upper arms of the four-link instead of being attached to the frame.
Behind all that tube is a Chevy 468 big-block fed by a twin-mixer propane-fed setup (see the propane bottle under the bag-everything sorta blends in the mud). Propane has some great advantages on the trail because it will run at any angle and doesn't leave an unburned fuel smell in back of the rig on the trail. The cone on top of the mixers below the air filter is crushed because this rig had just done a wheelstand, flipped over, and rolled down the hill. And it did it without a scratch, save for this cone. | 
It's hard to see, but imagine a 468 Chevy big-block mounted backwards, behind the driver, and feeding a TH400 2WD tranny. A driveshaft from the tranny runs to the front of the buggy where a V-drive system is mounted. From the V-drive, a driveshaft runs to a divorce-mount NP205 transfer case that supplies spin to the Rockwell axles. From this angle, you can also see the ends of the massive antisway-bar setup on the upper four-link control arms. | 
Night Stalker shocks also support the rear of the rig, along with another Evolution Machine & Fab four-link utilizing Evo joints. A matching fixed (non-steering) F106 axle provides strength in the rear, with a matching Detroit Locker and 7.17 gear setup in the front. |
Tech Specs
Vehicle: Evolution Machine & Fab-built buggy
Owner: Clayton Kraatz
Engine: 468 Chevy big-block
Tranny: TH400 tranny with V-drive
Transfer Case: Divorce-mount NP205 fed from V-drive
Front Axle: Rockwell F106, Detroit Locker, 7.17 gears
Rear Axle:Rockwell F106, Detroit Locker, 7.17 gears
Front Suspension: Night Stalker shocks, four-link utilizing Evolution joints, antisway bar built onto four-link
Rear Suspension: Night Stalker shocks, four-link utilizing Evolution joints
Winch: Warn 8274
Tires & Wheels: 49-inch Iroks on custom 16.5 wheels