The Detroit Speed Mustang Aluma-Frame (PN 032050) fits all '64-70 Mustangs and includes an aluminum suspension cradle, twin A-arms, forged spindles, coilovers, a splined sway bar, and a rack-and-pinion steering rack for $6,500. The standard system includes a set of high-performance shocks with DSE's own valving specs, but single-adjustable ($450), double-adjustable ($999), and remote reservoir ($1,300) units are available as well.
Detroit Speed’s Mustang was already stripped down before the install process began, but needless to say, anyone with a running Mustang will need to remove the engine and trans, along with the front suspension and subframe assembly. After disassembly, note that the rear lower control arm bolthole will be reused by the Aluma-Frame, so both the bolthole and its reinforcement flange must be retained. Before making any cuts around the shock tower, it’s a good idea to mark around the bolthole to make sure it’s not inadvertently cut off. It doesn't matter which shock tower is cut first, but DSE elected to start at the driver side.
Although it looks intimidating, cutting out the shock tower is very straightforward. Using a cutoff wheel, DSE recommends first cutting around the lower control arm mount, then working upward to the top of the tower. The factory seam between shock tower and inner fender serves as a handy cut line to assist with the process.
The shock tower, lower control arm mount, and engine mount sections detach as a single unit. Afterward, cut any remaining sections of the shock tower flush to the framerail. Removing the shock tower will also reveal several reinforcement flanges attached with spot welds, which must be drilled out. After detaching the flanges with a chisel, grind and deburr any sharp edges that remain. With the cuts on the driver side complete, repeat the process on the passenger-side shock tower.
The Aluma-Frame cradle attaches to the framerail using five bolts per side. This requires drilling four additional boltholes into the driver and passenger side of the framerail. To establish the hole locations, mock the Aluma-Frame into position by lining up the existing factory lower control arm bolthole on the framerail to the third bolthole (from the front) on the cradle. Bolt the Aluma-Frame to the framerails, and then check that the assembly is parallel to the rockers using a tape measure and a straightedge. Next, mark the holes with a transfer punch and hammer.
On later-year Mustangs, there may be some interference between the front edge of the Aluma-Frame and the factory crossbrace that ties the framerails to the radiator core support. Mark this area with a marker, and trim back the bracing with a cutoff wheel if necessary.
With the Aluma-Frame removed, locate the punch marks and drill ⅛-inch pilot holes before repeating the process with a larger ¼-inch drill bit. The hole closest to the front of the car requires cutting through a small section of the factory reinforcement flange with a 1.5-inch hole saw. The goal is to cut through the flange without cutting into the framerail. Next, cut into the framerail using a ¾-inch hole saw and remove the cut section of the factory flange with a chisel.
While the second hole from the front can be drilled using the same ¾-inch hole saw, the two holes closest to the rear of the frame require a larger 1.375-inch hole saw. The location of the rear-most hole will create interference with the stock steering box bolthole, but since it won’t be reused it’s OK to cut through it. When cutting through the sloped sections of framerail, hold the drill as close to vertical as possible.
After mocking the Aluma-Frame back into position, drill pilot holes from the bottom of the framerail to the top of the framerail using the supplied drill guide. Next, finish drilling the four crush tube holes from the top side of the framerail using a ¾-inch hole saw.
The Aluma-Frame uses a billet steel adapter plate that bolts to the top of the framerail, and serves as a support structure for the upper control arms and coilovers. To enhance the rigidity of the framerails, DSE includes four crush tubes (per side) that slide into the framerails.
Insert the crush tubes into the bottom side of the framerail, then screw them into threads in the upper adapter plate. A DSE spanner wrench is included with the Aluma-Frame system to make tightening the tubes a breeze. Next, stitch and plug weld the crush tubes to the framerail.
The upper adapter plate bolts to the framerail using supplied Grade 8 hardware. After bolting it down, locate the upper coilover mounting hole and use a transfer punch to mark its spot on the upper framerail. Afterward, remove the adapter plate, drill out the marked location with a ¾-inch hole saw, insert the coilover mount crush tube, and weld it in place from the bottom side of the framerail. Finally, reinstall the adapter plate before welding it to the framerail.
With the bulk of the cutting and welding complete, it’s time to start assembling the suspension. Secure the Aluma-Frame to the chassis using the supplied hardware, then install the lower control arms. The Aluma-Frame system includes bumpstops that function as progressive-rate springs should the suspension ever bottom out. It welds to the outboard side of the framerail, and locating it involves compressing the control arm upward and aligning it to the bumpstop pad on the control arm. Mark the corresponding location on the framerail, and weld the bumpstop bracket in place.
The Aluma-Frame system replaces the mushy factory steering box with an ultraprecise DSE rack-and-pinion unit. It secures to the frame using two Grade 8 bolts and some isolating washers to reduce vibration.
After installing the steering rack, slide the sway bar and Delrin bushings into the front of the Aluma-Frame assembly. To properly square up the bar, make sure that it protrudes 2.8 inches from the bushing on each side, then install the split-lock collars to prevent any side-to-side movement. Next, slide the sway bar arms over the splined section of the sway bar before bolting the endlinks to the lower control arms.
The upper control arm bracket bolts to the framerail adapter plate using a pair of shims stacked between it and the adapter. The bracket features slotted holes, which enable it to slide forward and rearward for easy caster adjustment. DSE recommends setting the proprietary Speed-Lign adjusters in the center groove for a nominal caster setting of zero.
Installing the coilover assembly is as easy as bolting the shock eyelets to the lower control arm on the bottom, and the upper control arm bracket on the top. By offering 6 inches of suspension travel in addition to a rock-solid cradle, Aluma-Frame–equipped Mustangs promise outstanding ride quality and handling.
Like the control arm bracket, the upper control arms also use DSE’s Speed-Lign system for simple camber changes. For baseline tuning, DSE recommends setting the adjuster in the first outboard groove for a nominal camber setting of ⅛ inch. When sliding the control arms into the bracket, they may require a gentle tap from a mallet.
Located at mounting points for the upper control arms and the upper control arm brackets, DSE’s Speed-Lign system makes on-track camber and caster tuning a reality. With this slick arrangement, the bolts are located by washers that look like ninja stars to ensure that once alignment is set, it doesn’t move around.
After bolting the spindle onto the ball joint, thread the tie-rod ends 1-inch deep into the steering rack. Finally, insert the outer tie-rod end onto the steering arm, and tighten down the castle nut before installing the cotter pin.