Roadster Shop SPEC Series Tri-Five Chassis Swap

When Chevrolet introduced the all-new ’55 Chevrolet it was a leap in technology along with new and exciting features like the optional compact V-8 we know today as the small-block Chevy. For its time, the 1955-’57 Chevy had a state-of-the-art chassis and suspension system that still delivers today in terms of cruising comfort. However, it isn’t much on handling when it’s time to blast through a canyon pass. Time and technology in the automotive aftermarket has passed up the Tri-Five Chevy’s original underpinnings, and we’re ready for a fresh start. We want to have fun.

Introducing Roadster Shop’s trio of chassis options for the Tri-Five Chevy: Spec, Revo, and Fast Track series frames. Vision and budget determine which chassis is for you. Hot Rod Specialties in Upland, California, has opted for the Spec Series chassis for a ’56 hardtop, which is an affordable means to getting into a high-performance aftermarket chassis without selling off the farm. The Spec Series chassis is available for all 1955-’57 Chevy sedans, hardtops, convertibles, station wagons, and the Nomad.

What makes Roadster Shop Spec Series frames unique is how they are engineered and manufactured. The Spec Series chassis is comprised of various different pieces of square and rectangular tube stock that add up to a rigid frame. Chassis strength is derived from these parts and the corresponding 0.125-inch wall thickness. These pieces are joined via crisp laser cuts and interlocking segments, which yield a precision fit.

This isn’t just about perfect fit and strength, but also economics and how to build a more cost-effective chassis. The Spec Series chassis is priced to start at $9,995, and when you examine what it would cost you to modify an original Tri-Five Chevy chassis, it makes more economic sense to order the Spec Series and roll it underneath your classic Chevy.

Joel Rode of Hot Rod Specialties has taken delivery of the chassis, disassembled it, had it powdercoated, reassembled it, and performed the body drop. The car is now in a Southern California body shop being prepped and painted in a delicious two-tone scheme. It will be returned to Hot Rod Specialties for final assembly once the body is in paint.

1.The Roadster Shop Spec Series chassis employs a refined engineering approach using the latest design and manufacturing technology to build the light, strong, and easy-to-install chassis system for 1955-’57 Chevys. The chassis arrives fresh off the truck ready for paint or powdercoat.

2.Proprietary suspension geometry has been engineered into the chassis to provide a great balance of ride quality and handling performance. What this means for you is a vastly improved ride and handling. You will never get this balance from your Tri-Five’s original chassis. The rearend is a large-bearing Ford 9-inch design with 31-spline axles.

3.The four-link coilover rear suspension eliminates leaf springs and conventional shocks, giving you a much more supportive chassis. Check out the precision CNC laser-cut and contoured crossmembers and chassis bracing, which allows for 3-inch exhaust plumbing. The Spec Series chassis uses factory body, bumper, and core support mount positions for precision bolt-on installation.

4.Joel Rode of Hot Rod Specialties (Upland, California) chose to disassemble the chassis and have it powdercoated prior to final assembly. At this point, he has begun the installation of chassis components, including the optional brake line plumbing from Roadster Shop.

5.The assembly can be challenging after you’ve had the control arms and other chassis components powdercoated. It is best not to powdercoat inside the control arm pivots, which makes polyurethane bushing fitment tricky. It’s a good idea to wear protective gloves when you’re installing the bushings coated silicone lubricant. The lubricant gets everywhere and is difficult to wash away.

6.Roadster Shop makes front-end alignment easy with upper control arm eccentrics, which adjust and lock-in caster and camber adjustments.

7.With the upper control arms and eccentrics installed, it is easy to see how caster and camber adjustments are made. Once the four eccentrics are properly adjusted and locked down it is nearly impossible to disturb the alignment.

8.Single-adjustable coilover shock installation begins at the top mount as shown, with the spacer, bolt head, and locknut installed like this.

9.The bottom shock mount is bolted to the lower control arm.

10.The Wilwood Pro spindle is attached to the upper and lower control arms and secured with castle nuts at the ball joints. Tighten the castle nuts and install the cotter pins.

11.The power rack-and-pinion steering unit bolts to the crossmember in front, as shown here. Power steering lines will be installed once the LS3 and 4L65E have been decked.

12.The antiroll bar is installed next and tied to the frame and lower control arms.

13.The sway bar bushings are lubricated with silicone lubricant to eliminate any noise potential.

14.The front suspension and steering have been completely installed and are ready for brakes and rolling stock. This can all be done in a matter of a couple of hours.

15.Joel readies the four-link suspension and rear axlehousing for installation. He suggests attaching the lower control arms to the axlehousing first. The coilovers have been bolted to the chassis, which makes securing them to the axlehousing easier.

16.We’re using a floor jack to support the rear axlehousing, which makes it easier to secure the coilovers and upper control arm links. We have a Currie 9-inch third member waiting in the wings with 3.50:1 cogs with a limited-slip differential and 31-spline hubs.

17.The coilovers are bolted to the axlehousing before moving on to the upper control arm links.

18.Joel connects the upper control arm links to the axlehousing and tightens all the fasteners. The Roadster Shop four-link suspension provides stability and way better handling than those old rusty leaf springs and shocks ever did.

19.All Roadster Shop brake line kits are pre-bent per each chassis and mounted before shipping to the customer. This is a nice labor-saving option you can order with your chassis.

20.The brake lines run along the axletubes and will transition to the brakes via flexible braided stainless steel hoses or bent and fixed steel lines.

21.Because the chassis has been powdercoated, we’re chasing all the threads in order to facilitate bolt and screw installation.

22.These optional brake line kits come with billet aluminum mounts.

23.The best time to deck the engine and transmission is when you have a bare chassis. Joel has opted for the Chevrolet Performance 430-horse Connect & Cruise LS3 (6.2L) and 4L65E transmission (PN CPSLS34L65E).

24.We’ve opted for polyurethane body mounts from Energy Suspension, which will outlast this build. Polyurethane bushings and mounts are harder than rubber, yet they offer unending durability.

25.The LS and accessory drive clear the steering rack nicely. Always check engine, transmission, and chassis clearances before buttoning your project up. It is easy to overlook oil pan-to-chassis clearances, which are more easily corrected before the body goes on.

26.The completely assembled chassis is ready for the body drop. Joel has installed available rolling stock (dusty old tires and wheels) for mobility purposes.

27.Joel did some minor correcting to get all the body mounts lined up. It is remarkable how easy it is to drop the body on when you have the right equipment.

28.The body is slowly lowered into position and all the body mounts are checked for proper alignment. Alignment should be spot on to where the body bolts drop through without interference.

29.The body mounts can be manipulated with a dowel rod as shown. Although the Roadster Shop Spec Series chassis is precision made, not all of these old Chevy bodies yield the same kind of fit, especially if they’ve been in an accident or had their floorpans replaced.

30.Our LS3 clears the firewall nicely without any interference issues. This chassis is engineered to accommodate virtually any GM engine/transmission combination imaginable, which means you can deck a small-block, big-block, or an LS engine.

31.We like the nice clean fit of the LS3 and 4L65E. And because the transmission crossmember offers flexibility, you may opt for any GM transmission imaginable, including those classic Muncie four-speeds and Turbo-Hydramatic three-speeds.

Photography by Jim Smart