2003 Chevy Silverado Stock Floor Body Drop - Low Job
How To Body-Drop Your Silverado The New-Skool Way
From the September, 2005 issue of Sport Truck
By Mike Finnegan
Photography by Sadistic Iron Werks
When you absolutely, positively, undoubtedly have to own the lowest truck on the block, accept no substitutes because a body drop is the only answer. It's one thing to set your truck up with an adjustable suspension system that allows you to ram the framerails into the tarmac at will, but it will never unleash the unbridled joy that comes with tuckin' a ton of rim and lugnut that only a body drop can deliver. Channeling or body-dropping the bed and cab of your truck down over the framerails several inches is the epitome of custom truck building, a modification that requires near complete disassembly of your ride, hacking the floor out of it and welding it all back together. It's definitely a mod that requires total commitment because once it's done, it's tough to undo. Body drops are not for the faint of heart, weary of warranty, or mechanically inept. Those of you who are handy with a MIG welder and associated handtools should have no problem performing a body drop using a little common sense, a tape measure, and this article as a guide.
We'll assume that if you're contemplating a body drop your truck already lays framerail with ease. This is something that needs to happen before you break out the plasma cutter or Sawzall and start cutting the sheetmetal on your ride. Getting your truck as flat on the pavement as possible beforehand will decrease the number of inches you'll have to body-drop your truck in order to get the rockers on the pavement. Keep in mind that the smaller the body drop, the more comfortable your truck will be to drive afterward.
Decades ago, hot rodders pioneered the art of channeling the body of their cars down over the framerails by raising the sections of floor directly above the framerails. Then, by lowering the body mounts, the body could be reinstalled onto the framerails several inches lower than stock. In the early '90s, mini-truckers took this modification to a new low (pun, definitely intended) by cutting the entire floor of their truck's cab loose from the rocker panels, rear cab wall, and firewall, raising it upward several inches, and then welding it permanently back into place. Those diehard mini-truckers made the mod their own and called it a body drop. A traditional body drop will literally decrease the amount of headroom and legroom inside the cab of your truck, and consequently make it less comfortable to drive. The same goes for the bed, too. If you have a tonneau cover and still want to pack the bed full of gear, then keep in mind that the depth of the cargo area will decrease substantially following a body drop.
There are other ways to achieve the same level of low that a traditional body drop or channel job will deliver and gain some much-needed interior comfort. It's commonly referred to as a "stock floor" body drop, and while the name doesn't exactly ring true (the floor is still modified in several areas), it's still a viable option that is quickly gaining popularity within today's custom truck crowd. Certain variations of the stock floor body drop entail lowering the cab mounts and sectioning the framerails of the truck to allow the cab to sit lower than it did when stock. Additionally, the driveline tunnel is raised upward so that when the cab is set downward in its new position on the chassis, the driveshaft has room to move about when the suspension is raised and lowered. The main benefit of a stock floor body drop is that unlike a traditional body drop, a major portion of the floor remains intact and this translates into a more comfortable driving experience. Also, you won't have that ugly step up into the cab, which is visible when the doors are open, that comes with a traditional body drop.
Sadistic Iron Werks of Hesperia, California, snapped these photos of their favorite way to lay a fullsize Chevy's rockers on the pavement. If you want to get technical, you could label this method as a combination channel/stock floor body drop. There is enough gap between the floor and framerails of 2000-and-later fullsize Chevy pickups to lower the cab mounts 1-7/8 inches without modifying the framerails. The only other major mod needed is to channel four small sections of the cab floor 3/4 inch to allow the cab to sit back down onto the cab mounts, after they are lowered 2-1/2 inches. From the inside of the truck, you can barely even tell the floor has been modified beneath the carpet. Also, unlike a traditional body drop, all of the interior paneling fits right back into place without modification. Without a doubt, this is probably the easiest and cleanest way to drop the cab of a fullsize Chevy and maintain driving comfort. The bed floor of this Chevy was raised 6 inches and then bolted back onto the frame atop 3-1/2-inch spacers. This puts the bed at the same level as the cab, while eliminating the need for any holes in the floor for the step notch in the framerails. Whatever you call it and however you achieve it, a body drop is the ultimate low and this is just one clean way of performing one. There's no doubt there are a hundred other ways to do it, so check out the photos and use Sadistic's tips to perform your own low job.
1.The guinea pig for this...
1.The guinea pig for this article is a standard cab '03 fullsize Chevy Silverado. Sadistic already laid the framerails of this truck on the ground with airbags and a 4-inch step notch. The truck is tucking a set of 22-inch wheels and 265/35R22 tires, which are 29 inches in diameter.
2.According to the tape measure,...
2.According to the tape measure, the rockers needed to move down about 2-1/2 inches to drag on the pavement.
3.There was nearly 2 inches...
3.There was nearly 2 inches of air space between the bottom of the cab floor and the top of the framerails. That meant that we could drop the cab approximately 1-7/8 inches, before the floor would hit the framerails. This wasn't nearly low enough to put the rockers on the ground, so the additional 3/4 inch had to be gained by raising the portions of the floor, just above the framerails where it would hit.
4a.On a Chevy, the cab mounts...
4a.On a Chevy, the cab mounts are pretty tall and run from the top of the framerail all the way down to the bottom, which means we couldn't cut the bottom portion of the mounts off the exact amount of the total body drop. The mounts were marked, cut, and welded back onto the framerails in a position that was 2-1/2 inches lower than they were from the factory.
5.With the cab mounts repositioned,...
5.With the cab mounts repositioned, it's time to modify the cab to allow it to be mounted in its new, lower location. After the interior was removed, including the carpet, the floor was cleaned so that the modified areas could be marked off.
6a.The framerails were traced...
6a.The framerails were traced with a marker, from beneath the floor and also on the inside to give a guide for cutting. The areas between the front and rear seat frame mounts needed to be raised upward to allow the cab to be dropped downward over the 'rails.
7a.With the cab suddenly moving...
7a.With the cab suddenly moving downward, there wasn't enough room between the firewall and the tires anymore. The outer diameter of the tires was marked on the sides of the firewall, so that appropriate sections of steel could be removed, re-contoured in steel, then welded in place.
8a.The firewall was cut out...
8a.The firewall was cut out behind and directly above the tires, then 18-gauge sheetmetal was trimmed to fit the area. A half-moon-shaped side panel was welded into the side of the firewall first, extending inward into the cab. Next, a flat, rectangular steel panel was tack-welded to the top of the arch and bent to its contour, since the heat from the weld made it flexible.
9.Once the fabricated wheeltubs...
9.Once the fabricated wheeltubs were completely MIG-welded into place, several inches of additional clearance were added into the engine compartment. A die grinder was called into play to smooth the welds.
10.Next, the cab was lifted...
10.Next, the cab was lifted off the frame, so that the floor could be cut and modified without the worry of chopping fuel lines, brake lines, or wiring.
11.The transmission tunnel...
11.The transmission tunnel had to be raised approximately 2 inches from the firewall to the middle of the cab. A 4-inch Makita grinder fitted with a cut-off wheel made quick work of the sheetmetal, but you could also use a plasma cutter or reciprocating saw as well.
12a.At the front of the transmission...
12a.At the front of the transmission tunnel, a flat piece of 2-inch-wide sheetmetal was bent twice and welded in place to reconnect the tunnel to the firewall. The sides of the tunnel received pie-cut strips of sheetmetal as well.
13a.Next, the areas of the...
13a.Next, the areas of the floor directly above the framerails were cut out. Rectangular sections of sheetmetal were again cut and bent to not only cover the slots in the floor, but also add 3/4 inch of additional height to these areas.
14.Once the work on the floor...
14.Once the work on the floor was completed, this was what everything looked like. Up front, you have a pair of wheeltubs that protrude into the cab behind the dashboard, but the floor was only slightly modified and was easily covered up by the factory carpeting.
15a.Now that the cab had been...
15a.Now that the cab had been modified to slip down over the frame, we needed to address the front clip of the truck, which also needed to be moved down 2-1/2 inches. The easiest way to move the entire front clip, including the radiator, downward is to cut the frame horns just behind the radiator. Once the front section of frame was cut loose from the rest of the frame, it was re-positioned and gusseted back together. This effectively completed the body drop of both the cab and the front clip.
16.Body-dropping the bed is...
16.Body-dropping the bed is a simple affair. The guys at Sadistic chose to perform a traditional body drop, which means that they cut the entire bed floor loose from the front bulkhead and side walls, raised it up 6-1/2 inches, then reattached it. While the floor only needed to move 2-1/2 inches to equal the body drop of the cab, the floor was raised an additional 4 inches, so that once it was re-mounted on spacers, no holes would have to be cut in the floor for the 4-inch step notch in the framerails. It's a clean look that really keeps the inside of the bed functional.