What do all really tall trucks have in common? Big freakin' tires. You've got to have huge-by-large rolling stock if you want to build your own monster truck. Having big tires used to mean that your truck was rolling on 40s, and you were really livin' large if you were sitting atop a set of 44s. These days, that's child's play. Forty-fours are now 8 inches too small if you want to really be the man.

The discovery of Michelin's XZL all-terrain special-service tires by off-roaders changed the game and upped the ante for lifted-truck rockstar status. These tires were originally designed for emergency-service and military vehicles that operate in sand, mud, and deep water. By pure coincidence, they work perfectly for a serious off-road machine or monster street vehicle; they are huge and fit on 20-inch rims. At 52 inches in diameter and with a load rating of 14,540 pounds at 110 psi, these radials are the biggest tires you can get for a set of dubs.

Jason McCoy of Big Bear Customs understands the importance of picking the right rolling stock. His shop has turned out a number of outstanding project trucks over the last decade, each one tucking or towering over a set of big wheels. His latest project is this '05 Ford F-350, a ride that thus far has spent more time in his shop than it has on the road. After plunking down $42,000 at the local dealership, Jason went with the Ford because he wanted to build his own monster that was clean enough to get into a magazine. While this one doesn't have an outrageous interior or abundance of body mods, it does have a flashy look and sanitary fabrication work, which is why we chose it for the cover of Sport Truck. It also didn't hurt that unlike some of the other ridiculously large trucks we've seen lately, this one has a front driveshaft and the 4wd actually works.

The backbone of the monster lift is a tubular subframe that bolts to the factory chassis. Jason was adamant about not modifying the strong structure of the Ford and going the extra mile to ensure his suspension work would bolt onto it, and it paid off in spades. Not only is the setup serviceable, but he was also able to remove the parts to have them powdercoated without messing with the stock parts. The subframe is crafted from drawn-over-mandrel 2.250-inch tubing, which was bent and MIG-welded together with abundant crossbracing. The subframe attaches to the chassis at the factory leaf-spring mounts because the springs are no longer present. Jason ditched the springs and replaced them with 24-inch Goodyear air springs and attached the axles to the chassis via front and rear four links with wishbones. The suspension control comes courtesy of King 2.5-inch chrome dampers that were valved specifically for the massive air springs. To keep body roll in check, Jason fabricated adjustable front and rear sway bars that pivot using stainless steel rod ends.

So how does all of this trick suspension fabrication and engineering work out on the road? Well, the 'bags provide 24 inches of solid suspension travel, and along with the massive tires this truck measures 48-inches taller than a stock Super Duty. So on the one hand, we'd assume the truck is big enough to be gangly around corners, but the suspension is soft enough to ride plush. Jason admits that the hydraulic steering system is smooth but a tad too quick-reacting at high speeds. So this truck is trailered to truck shows, but Jason mobs it around his hometown without too much drama.