1970 Chevy Chevelle - 6 Point Roll Cage - Build & Install

1970 Chevrolet Chevelle Driver Side View

Once again, ask and you shall receive. This month we show you how to install a six-point rollbar from S&W Race Cars along with upgrading the Chevelle with SFI-approved seatbelts from JAZ Products.

To ensure that we installed our S&W rollbar correctly, we turned to M&J Auto Body for guidance. The M&J crew transformed our Chevelle from junker to jewel in last year's Paint & Body special, so we knew that they were good fabricators.

Available directly from S&W Race Cars, we ordered a complete rollbar setup (part No. 11-003) made especially for our '70 Chevelle. The kit includes a main hoop, rear braces, side bars, seat crossmember and six steel mounting plates. The bars are made of 1.75x0.134-inch-wall mild-steel tubing and feature notched tube ends (where applicable).

Begin the rollbar install by prefitting the main loop and the side bars to ensure that everything is correct for your chassis. The bar(s) will need to be trimmed slightly, but the parts are generally ready to go. In fact, the end of the side-bar tubes and the crossmember that join to the main loop have already been "fish mouth" radius-cut, thus easing installation. After we trial-fit the rollbar, we removed the carpet, front bench seat and the headliner to gain clearance for the rollbar install. Ripping out the nasty old carpet and headliner was needed anyway because our Chevelle is going to get a new low-buck interior kit in the next few issues. Stay tuned.
Begin the rollbar install by prefitting the main loop and the side bars to ensure that eve
With the carpet removed, begin the rollbar install by grinding the floor to bare metal in the area where the loop will be welded to the floor (just behind the front seat but ahead of the rear seat). The area must be free from paint and gunk so that the steel mounting plates can be installed with a good, clean weld.
With the carpet removed, begin the rollbar install by grinding the floor to bare metal in
Because the mounting location of the mounting plates is in a contoured area of the floorboard, you'll need to bend/sculpt the mounting plates to conform to the floorboard shape. We marked where the plate needed to be bent and then removed the plate from the car to make the proper modifications.
Because the mounting location of the mounting plates is in a contoured area of the floorbo

After you've properly contoured the two mounting plates for the main rollbar loop, tack-weld them into position. Do not weld them fully into place yet, just in case some minor adjustments need to be made. With the plates tack-welded in position, carefully mark the angle of cut needed to get the main rollbar loop to sit flush on the plate(s).
After you've properly contoured the two mounting plates for the main rollbar loop, tack-we
After making the proper trim marks, remove the main rollbar loop from the car and make the necessary angled cuts. Because the tubing is made of mild steel, you can make the cuts with a hacksaw, but it will take plenty of arm effort. We used a high-speed radial cut-off wheel to make all of our tubing cuts, which made the installation process much easier.
After making the proper trim marks, remove the main rollbar loop from the car and make the
Once the ends of the main rollbar loop have been angle-cut, refit the loop to make sure that the ends sit flush with the mounting plates. Next, fully weld in the mounting plates and then weld in the rollbar loop.
Once the ends of the main rollbar loop have been angle-cut, refit the loop to make sure th

With the rollbar loop welded in place, position the rollbar crossmember at shoulder height. If you add a four- or five-point seatbelt harness (as we are doing), the crossmember is the point at which you'll need to attach the shoulder-harness part of the restraint system.
With the rollbar loop welded in place, position the rollbar crossmember at shoulder height
Once the crossmember is in the proper location, have a buddy hold the bar while you weld it in place. Notice the Speedglas welding helmet--it's the trickest thing we've seen in a long time. The helmet has a special viewing screen that is unshaded when you are not welding, such as when positioning your welding work. Then, the instant that you strike the weld, the viewing screen turns to its predetermined shade (number 11 shade in our case). As soon as you stop welding, the viewing screen instantly returns to its unshaded clear-view screen.
Once the crossmember is in the proper location, have a buddy hold the bar while you weld i
After the main hoop is welded in place, trial-fit the side bars. Notice how the end of the side bar that attaches to the main rollbar loop is "fish mouth" cut to allow it to conform around the main rollbar loop. The other end of the side bar will need to be angle-cut to properly align with the front-mounted steel mounting plates.
After the main hoop is welded in place, trial-fit the side bars. Notice how the end of the

Just as with the main rollbar loop, the side bars need to be welded to steel mounting plates. For our application, the two front mounting plates (one for each side of the car) only needed slight bending to conform with the contour of the Chevelle's floorboard. After you've mocked-up the side bars and determined the proper location of the front mounting plates, weld the plates into place.
Just as with the main rollbar loop, the side bars need to be welded to steel mounting plat
After the side bars have been mocked up, angle-trimmed to length and the front mounting plates welded into place, carefully weld the fish-mouthed end of the side bar to the main rollbar loop. Notice the thick piece of metal located behind the rollbar loop. The metal plate prevents burning the doorjamb paint, weather stripping and/or door panels while you weld. Remember as you weld that dozens of hot metal sparks will be flying off, so carefully cover anything that you don't want burned or singed.
After the side bars have been mocked up, angle-trimmed to length and the front mounting pl
Once the top end of the side bar has been welded to the rollbar loop, carefully weld the bottom end to the front mounting plate. Notice how the end of the side bar fits flush with the mounting plate. The better the pieces fit together, the stronger (and better looking) the rollbar assembly will be.
Once the top end of the side bar has been welded to the rollbar loop, carefully weld the b