1955 Chevy Bel Air Project - Framerails

1955 Chevy Bel Air Project Box Steel Tubing Rails

The first step is to assemble the pieces that make up the outer rails on the chassis jig. The rails are made of box steel tubing and offer superior rigidity over the stock rails.

The first step is to assemble the pieces that make up the outer rails on the chassis jig.

When the Tri-Five chassis debuted in the fall of 1954, it was a revolutionary design that offered the best handling and riding suspension available at the time, at a much lighter weight than previous Chevrolet car chassis. Flash forward almost 60 years. While some of the same basic designs are still used today, the whole chassis itself has become outdated in the handling department. While there are bolt-on components available that will drastically improve the handling qualities of a '55-57 Chevy, you still have the issue of dealing with an almost 60-year-old steel structure that has seen a lot of stress and abuse from driving, racing, and (in some cases) years of sitting.

Addressing this issue, aftermarket companies like Fatman Fabrications have come out with all-new chassis for the Tri-Fives. Not only do these assemblies feature modern steel construction, but also cutting-edge design with the latest technical innovations in suspension, steering, and braking components.

The eventual goal for our Project '55 is to have a car capable of quarter-mile, autocross, and comfortable street driving. The original frame on our '55 had been hacked on a bit, and while still usable, didn't offer the level of adjustability and function to handle all the things we have in mind for the car. We contacted Brent Vandervort, the founder of Fatman Fabrications, about what to do.

Vandervort started Fatman Fabrications in 1985 to build new chassis for street rods. Having built numerous cars for friends on the side, he knew what was needed when it came to an up-to-date chassis for classic cars. As his business grew, so did the product line, eventually including full bolt-in chassis for later-model vehicles like our '55. Now Fatman employs over 40 people at its shop just outside Charlotte, North Carolina, building some of the finest and strongest aftermarket chassis available.

Follow along as we see what goes into building a typical Fatman Tri-Five chassis, and explain all the advantages it has over a stock/modified stock frame.

Each piece has alignment tabs like these welded in so the rail pieces align properly for welding once they're set up in the jig.
Each piece has alignment tabs like these welded in so the rail pieces align properly for w
Using basic measuring tools and the alignment line down the center, the individual framerail pieces are lined up, then secured in the jig for welding. After they're secured, the pieces will be measured one more time to verify alignment before being welded. All it takes is for one little piece to be off, and nothing else will line up correctly during the frame's construction.
Using basic measuring tools and the alignment line down the center, the individual framera
With everything set, the rail pieces are tack welded together. In the initial construction stages, all parts are only tack welded, so if anything needs to be moved around to keep the frame true and measurements correct, only a small weld must be ground off. Only once everything is aligned, tack welded, then double-checked again for proper alignment and position will the chassis have the finish welding done.
With everything set, the rail pieces are tack welded together. In the initial construction

Before the crossbraces can be set in place, the outer rails must be positioned correctly apart from each other, and verified that they are parallel. The builders at Fatman are fanatical about taking measurements and making sure everything is correct, so every frame built will be as perfect as possible, and have no fitment or suspension tuning issues.
Before the crossbraces can be set in place, the outer rails must be positioned correctly a
With everything set, the mounting point for the first rear crossmember is located, measured, and scribe marked. The crossmember will be set in place, checked for alignment, then tack welded in place.
With everything set, the mounting point for the first rear crossmember is located, measure
At the front of the frame, the crossmember that mounts the rack-and-pinion and engine block mounts is set in place. Placement of this piece is critical, because if it's off, it will throw everything else out of alignment.
At the front of the frame, the crossmember that mounts the rack-and-pinion and engine bloc