Modern Rodding Tech
1970 Chevelle black with white double stripe
1. This car has stunning, custom-machined exhaust outlets that are precisely fitted to the rear panel of the body.
Finishing Touches
Project 1970 Chevelle Exhaust Wrapup … & a Few Other Tidbits
By RON COVELL PHOTOGRAPHY COURTESY OF ROADSTER SHOP
I

n previous articles, we’ve covered many details of this exceptional 1970 Chevelle built by Roadster Shop. This time, we’ll focus on some of the finishing touches that add just the right amount of sparkle. Many exhaust systems end with a polished round tip or a commercially available rectangular profile. These can look good, but the goal was to elevate this detail in a unique way. The team decided to machine custom exhaust tips from solid stainless steel—no small feat.

The exhaust tips were designed in CAD, and a test piece was 3-D–printed in polymer to verify size, shape, and fit. After passing all tests, the final parts were produced in metal. The design’s complexity required that each tip be machined in two parts, allowing the inner section to be hollowed. Holding these thin-wall parts during machining is challenging, so bosses were added on the sides of each piece to securely attach them to a machining fixture. After the shapes were fully machined, the bosses were removed and smoothed.

The parts were welded along the centerline and, after smoothing the joints, they appear as a single solid piece of metal. Once the tips were positioned and mounted, the valence panel under the bumper was scalloped to match the shape, with the edge of the opening flared and radiused. As shown in the photos, this creates a very sleek look for the ends of the exhaust pipes that blends smoothly with the valence panel.

The rear doorjambs have a vent, originally covered by a plastic grille. A plan was developed to replace it with a machined, polished aluminum grille, using custom sheetmetal receivers to ensure the grille sits flush. This detail isn’t visible when the doors are closed, but it’s a nice little surprise that appears whenever the door opens.

The engine in this car is a 454ci LSX, and a special badge was applied with this designation. These badges were placed at key locations—both under the hood and on the exterior bodywork. They were CNC-machined from aluminum, then polished, and the recesses were carefully hand painted. These have the look of factory-made badges and clearly signal that this build was done without compromise.

The photos reveal the details of how these were built, and we hope they inspire some ideas for your next project!

1970 Chevrolet Chevelle - Orange engine block with silver headers and black transmission undergoing restoration, showcasing Ridetech suspension components
2. The exhaust system was assembled in the usual way, running toward the rear after the headers were attached to the engine.
1970 Chevrolet Chevelle - Orange engine block with silver headers and black transmission undergoing restoration, showcasing Ridetech suspension components
3. The exhaust tubes are installed as high as possible in the chassis so that nothing hangs below the body.
3D Printed Exhaust Tip - RS Design Close-up of a white, textured 3D printed exhaust tip
4. A custom exhaust tip was CAD designed, featuring the Roadster Shop logo, and a prototype part was printed from polymer.
1970 Chevrolet Chevelle - Custom Exhaust Fabrication
5. Once the design for the exhaust tip was finalized, it was machined in two halves from a solid piece of stainless steel.
1970 Chevelle - Billet Oil Pan Detail A polished aluminum billet oil pan
6. The inside of the part was machined first, then the blank was flipped in the machining center to finish the outer surface. Six bosses remain on the outside of the blank, allowing it to be securely bolted to a fixture plate for the final machining.
1970 Chevrolet Chevelle - Stainless Steel Exhaust Details Polished stainless steel aftermarket exhaust tips
7. Here are the parts after machining was finished.
1970 Chevrolet Chevelle - Stainless steel exhaust tips and X-pipe detail
8. The upper portion of the exhaust tip has a boss with two threaded holes, allowing it to be securely fastened to the body of the car.
1970 Chevrolet Chevelle - Stainless steel exhaust tips and X-pipe detail
9. The halves of the exhaust tip have been TIG-welded together here.
1970 Chevrolet Chevelle - Stainless Steel Exhaust Tip A polished stainless steel exhaust tip
10. With the welds cleaned up, the part looks seamless.
1970 Chevrolet Chevelle - Exhaust Detail Close-up of a polished stainless steel Magnaflow exhaust tip
11. The valence panel below the rear bumper had to be notched to fit around the exhaust tips.
1970 Chevrolet Chevelle - Exhaust Detail Close-up view of a 1970 Chevelle's rear quarter panel
12. The notched area was capped, flared, radiused, and detailed.
1970 Chevrolet Chevelle - Exhaust Detail Close-up of a silver 1970 Chevelle's rear bumper
13. The valence panel is metalfinished here, and the fit with the exhaust tip is checked again.
1970 Chevrolet Chevelle - Black Chevelle exhaust detail showing polished stainless steel tip
14. The final fit is checked one last time after the body has been painted.
1970 Chevrolet Chevelle - Chrome exhaust tip details on dark gray metallic paint
15. It took a lot of work to achieve a fit this nice, but we think the results are worth it!
1970 Chevrolet Chevelle - Olive Green Metal Vents
16. Originally, the doorjambs had a cheap plastic cover for the vent. A custom aluminum grille has been machined, and a sheetmetal panel has been formed with a recess to allow the grille to fit flush.
1970 Chevrolet Chevelle - Exhaust Detail Close-up of a restored 1970 Chevelle exhaust
17. Here, the sheetmetal surround is held in place with Clecos as the grille is being fitted into the doorjamb.
1970 Chevrolet Chevelle - Black exterior detail showing chrome vent and door handle
18. With the finish work done, you can see how this grille adds one more beautiful detail, visible when the door is opened.
1970 Chevelle LSX Engine Badge - 454 cubic inch engine with 700 horsepower detailed in grey line art
19. Unique badging was designed to designate the powerplant in the car.
1970 Chevrolet Chevelle Exhaust Detail - CNC Machined Exhaust Manifold Flange
20. This badge, for the air cleaner, is being machined from billet aluminum.
1970 Chevelle SS 454 - Emblem Detail Close-up of a weathered 454 engine displacement emblem
21. The edges of this part have been trimmed, and it is being carefully shaped over a wooden block to fit snugly against the curved top of the air cleaner.
1970 Chevrolet Chevelle SS 454 Close-up shot of the iconic SS and 454 LSX badging on a black Chevelle
22. With the badges polished and some color added, they really pop!
1970 Chevrolet Chevelle - LS6 454 Engine Bay Detail
23. Elegant finishing touches like these can really make a car stand out from the crowd.

Modern Rodding
VOLUME 7 • ISSUE 68 • 2026