We previously introduced Mark Stielow’s latest Pro Touring project, which is based on an Oregon-found, original-paint Fathom Green 1969 Camaro that was remarkably preserved, but had long ago lost its original 307 small-block.
Stielow doesn’t build poseur Pro Tourers, and this one is no different. Its track capability will be rooted in a completely upgraded chassis incorporating a four-link rear suspension, coilover front suspension, and strengthened body structure to enable more precise suspension tuning. It is also built to support the 650 horsepower and 650 lb-ft of torque from a Corvette Z06-derived LT4 crate engine from Scoggin-Dickey.
The fab work for the chassis and suspension upgrades are being handled by Detroit-area Sled Alley, and that’s where we’ve caught up with the project for this, the second installment of the build series. After being stripped and sent off to the mediablaster, the chassis was strategically sliced open in several areas to make room for just about everything in Detroit Speed’s catalog tagged “fits first-generation Camaro,” from the QUADRALink rear suspension and deep tubs in the rear to the hydroformed, coilover-capable front subframe, and subframe connectors to link them together.
That meant cutting out the rear framerails and stock rear wheeltubs and opening up the floor for the frame connectors. The front subframe’s installation was a comparative cinch, bolting up to the stock attachment points.
“We’ve used Detroit Speed components on several of Mark’s cars and you can tell they’ve done their homework,” says Sled Alley founder Matt Gurjack. “The supplied templates and other supporting components are based on the experience of building plenty of cars, and while there’s always custom fabrication to contend with on a project like this, the accuracy of their kits makes the project go much faster.”
Attention to detail is the essential yang to a high-quality kit’s yin. Making room for the wheeltubs requires cutting into the rear framerails, while the installation of the QUADRALink’s suspension crossmember involves cutting out a pretty large swath of the upper trunk floor. Similar surgery is required to the floor, which must be cut open to install the frame connectors.
Oh, and the installation of the suspension crossmember means the elimination of the original rear shock mounts, while the installation of the tubs requires a custom, narrower fuel tank. All of that requires prep work to ensure the car is square and level before the first cut is made, as well as careful measurements to make sure those cuts are made on perfectly centered lines. Talk about pressure.
Each element of the chassis upgrades outlined in this story would warrant its own tech story, but we just don’t have the room. Instead, we’ve provided a highline overview of the various upgrades and some of the tips and tricks that go into an accurate installation.
As the project progresses we’ll outline the suspension, engine, and other drivetrain elements that are going into the dark-green F-car.
That reminds us that Stielow hasn’t yet named his most recent project. Previous cars have carried names such as Jackass, Mayhem, Hellfire, and Red Devil. He floated the name Jaded to play off the car’s green hue, but he’s open to ideas. We’ve suggested Envy or Envious, as additional plays on the green theme, and while there are no bad ideas in brainstorming they didn’t get very high up the consideration flagpole. Let us know your thoughts and ideas and we’ll pass them along.
But seriously, Mark: Envy. It works. Trust us.
01. Stielow’s latest project began life as a surprisingly preserved, original-paint 1969 Camaro found in Oregon. The original 307 was long gone and there were a few period upgrades from the 1970s still bolted to it, but the body was 98.5 percent rust free, making it the perfect Pro Touring candidate. It was delivered to Detroit-area Sled Alley just before the 2016 SEMA Show with the indiscriminate small-block already removed. Time to warm up the welder.
02. Sled Alley wasted little time in dismantling the Camaro, stripping everything from the body in preparation for a trip to the mediablaster. More than a few dead mice were found in the body, along with a few .22-caliber bullets. Because the patina of the original paint will be retained, the exterior was carefully taped and tarped to ensure only the undercarriage and the firewall will get stripped.
03. Back from the blaster, hours were spent blowing out leftover stripping media from all of the car’s nooks and crannies. Then, the painted exterior was wrapped in plastic in order to seal the cleaned metal with a black epoxy primer.
04. With the bottom of the car primed, work moves on to the chassis modifications required to install a complete Detroit Speed QUADRALink rear suspension, deep tubs, and a Strange 9-inch rear axle. That means cutting out the original rear wheeltubs, but not before the car was squared on the shop floor, using a digital level and shimmed jack stands, to ensure every measurement and resulting cut would be straight and true.
05. On the interior, seatback support braces linking the package tray-area sheetmetal to the original tubs were cut out before the tubs themselves (arrow). Note, too, the protective 3M welding and spark protection paper, which is used on the rear glass and windshield to protect the original glass.
06. Here, the original wheeltubs have been cut out and lines scribed on the trunk floor (highlighted in yellow) to indicate where an upper mounting crossmember for the QUADRALink suspension will be located. The pattern of the wheeltub radius was also made. It will be moved inboard on each side to provide a guide for cutting out the additional 2 inches required for the new wheeltubs.
07. The rear suspension crossmember has been installed. It eliminates the original shock mounts, which makes the original measurements vital to locating the new suspension because the new crossmember spans the centerline between the original shock mounts. Detroit Speed’s templates and guidelines for the measurements are thorough and comprehensive, but some adjustments are inevitable on a nearly 50-year-old unibody muscle car.
08. The triangular corner pieces blended into the suspension crossmember aren’t part of the Detroit Speed kit but scratch-built by Sled Alley for a couple of reasons. First, they match the 45-degree corners of a stainless Rick’s Tanks that will go in later, and second, they leave room for routing a 3-inch exhaust system.
09. All of Stielow’s cars are built to run on the track—and run hard. As such, Sled Alley adds a pair of gusseted braces from the Detroit Speed suspension crossmember to the factory framerails. It’s a little extra insurance and chassis strengthening that makes the car that much more solid.
10. About 2 inches of the rear framerails must be cut out to accommodate the new, wider wheeltubs, as shown here. You can also see the strength penetration of the weld for Sled Alley’s additional brace between the suspension crossmember and the framerail. There will be little flex left in this unitized body structure.
11. More chassis reinforcements come with custom closeouts for the ends of the new suspension crossmember. Like the frame gussets, they’re not part of the Detroit Speed kit, but added by Sled Alley for an extra measure of strength and rigidity.
12. Closeouts for the carved-out framerails are included from Detroit Speed, but again, Sled Alley builds their own, mostly because each vehicle is slightly different and the custom closeouts are trimmed to the exact contours, eliminating the time needed to add small patches or extra welds to fill gaps.
13. Here, the left-hand wheeltub has been installed. Prior to welding it, a line is scribed around the flanged edges. Then, the tub is pulled out of place and pilot holes for spot welds are drilled between the scribed lines and the edges of the cut out tubs. Also visible here is one of the vertical suspension mounts for the QUADRALink suspension. There’s a complementing mount on the opposite side of the floor.
14. The wheeltubs’ installation wraps up with replacing the seatback braces between the tubs and rear seat/package tray structure. Sled Alley modified and stretched the originals to make them fit.
15. The rear axle is shown mocked in place to check everything is square and mounted properly, including the Panhard rod bracket. The vertical rods on the rear of the axle simulate the mounting position of the shock assemblies. Everything with this part of the installation proved good to go, so it was on to the subframe connectors.
16. Unlike subframe connectors for third- and fourth-gen F-bodies that are mounted entirely below the floor, adding them to first-gen models requires routing them through the floorpans. The job starts with trimming the front seat mounting brackets and slicing slots into the floor. Sled Alley uses cutoff wheels for the job rather than a torch or plasma cutter. The cutoff wheel takes a little longer, but they believe it offers a cleaner cut that requires less follow-up work.
17. Kit-supplied templates provide accurate dimensions and location for the holes to cut in the floor, but the connectors themselves invariably require a little finessing to center them squarely for installation. Again, most of the variation is due to decades of chassis flex.
18. The Detroit Speed connectors are made of sturdy, 2x3-inch rectangular steel tubing with 0.120-inch wall thickness. As with all the welding for the fabrication work performed on the car, Sled Alley TIG-welds them in place. It takes more experience to nail down the technique, but shop founder Matt Gurjack prefers it for the greater heat control and cleaner results that require less “clean up.”
19. With the frame connectors in place, the new Detroit Speed front subframe was bolted to the body. Constructed with hydroformed framerails that are super stiff and very precise for mounting a coilover suspension and wheels up to 10 inches wide. It’s not a small investment, however, as the base subframe starts at $7,100 and optional setups can push the tally up to $8,850. Fortunately, all versions include the coilover suspension components, too.
20. The new front subframe is manufactured to accommodate—and includes with the kit—a rack-and-pinion steering system that improves steering control and feedback, reduces front suspension complexity, and reduces weight.
21. A custom touch that Sled Alley has built into several of Stielow’s previous cars is cutting out the right-hand corner of the cowl structure to create an unobtrusive mounting position for the reservoir tank for the engine’s dry-sump oiling system. There are no significant structural issues to contend with in this corner of the body, making it an ideal position for the tank, while also offering a weight balance advantage.
22. Sled Alley also took the time to clean up the Camaro’s firewall and fill in a number of holes that won’t be required with the new powertrain system. The hours are racking up on the project, with top-notch fabrication ensuring the car’s strength will hold up to the capability of a powertrain that the original engineers couldn’t have dreamt up 50 years ago.