Modernizing a ’66 Chevy takes more than bolting on a new chassis. The real work is in the support systems that make the truck usable: air suspension that can control a heavy Duramax-powered package, a fuel system that can hold pressure and flow without starving the engine, and an A/C layout that can be packaged cleanly before final sheetmetal starts. Here the focus is on 3/8-inch air management for faster lift and drop response, rotary height sensors that track true suspension position instead of relying on bag pressure alone, monotube shocks for better heat control and durability, and a large-filter, brushless-pump fuel system built to minimize pressure drop. Add the firewall bulkhead and mock-up HVAC parts, and the engine bay can be planned correctly before fabrication locks everything in.
The episode opens with an update on the LockJaw build schedule and the immediate fabrication plan. Gale Banks and the team are preparing the truck for Sean at Empire Fab, who will ultimately handle extensive sheet-metal work. To make that possible, the shop needs to mock up the major systems first so Sean can build around fixed component locations rather than work from a blank slate. Several parts are already sitting loosely on the engine, and the goal of this phase is to establish packaging for the suspension air system, fuel system, and air-conditioning hardware before the body is transferred to the new chassis.
The team frames this as a practical engineering step rather than cosmetic assembly. By opening the parts boxes now and understanding how each subsystem will mount and interact, they can define hard points on the truck and reduce guesswork later. That is especially important because the final truck will combine a heavy Duramax diesel, a custom chassis, a dump bed, and substantial underhood fabrication.
The first major subsystem is the Ridetech air suspension package. Ridetech began in 1996 as Air Ride Technologies and later expanded into coil-overs, changing its name to Ridetech in 2010. The kit includes an aluminum air tank, mounting brackets, soft air line, push-lock fittings, pumps, solenoids, and the electronic controls. The supplied brackets simplify installation because they can mount the tank around the frame rails without requiring the team to fabricate those supports from scratch.
A key decision was to use 3/8-inch NPT plumbing rather than the more common 1/4-inch size seen in many air systems. That choice is driven by vehicle mass. Because LockJaw uses a heavy Duramax, the larger passage size should improve airflow enough to raise and lower the truck in a reasonable amount of time. The team notes that 1/4-inch hardware is common, but for a truck this heavy, 3/8-inch capacity is more appropriate.
The system uses dual 12-volt DC Thomas pumps, each rated at 20.5 amps. The team describes these pumps as familiar and reliable, having used similar units in earlier water-methanol applications. Running two pumps provides the airflow needed to lift the truck's substantial weight. For mock-up, they are considering a single tank, but the broader design discussion includes dual tanks in the final version to preserve visual symmetry, especially when the dump bed is raised. That symmetry also matches the plan for dual charge-air components elsewhere on the build.
The air-management hardware includes eight solenoids and a four-way control assembly that independently manages each air spring. The team walks through the airflow path conceptually. Air from one or two pumps feeds the tank, with a check valve used to ensure flow only moves toward the tank. From there, tank pressure feeds the supply side of the manifold, and the delivery side routes air to the four individual bags.
The opposite side of the manifold handles sensing and exhaust functions. Pressure sensors monitor each bag so the control system can compare pressures corner to corner, while venting ports bleed pressure off to lower the vehicle. The team wants this manifold mounted where it remains visible in the finished truck because it is both functional and visually clean.
Ridetech's newer control package includes a 3.5-inch touchscreen interface and a separate control module that serves as the system's brain. This module works with the solenoid assembly and pressure sensors to automate ride-height changes and allow in-cab control. The touchscreen is intended to let the driver command presets, including dropping the truck fully to the ground. The pressure sensors themselves are notably compact, which should help with packaging in a crowded custom chassis environment.
The team then moves to the ride-height sensor kit, which represents a significant improvement over older pressure-only air suspension control methods. Traditionally, many systems inferred ride height by matching bag pressure at each corner. For example, if the right-front bag was at 80 PSI, the operator might try to match 80 PSI at the other corners. The problem is that equal pressure does not guarantee equal ride height because each bag behaves as a spring with its own effective rate and geometry.
Ridetech's solution uses rotary ride-height sensors with mechanical linkages that track actual suspension movement. The linkage pieces are designed to be highly universal. They can be cut, shaped, and adapted to suit different packaging constraints, then locked into place. In operation, one end of the linkage mounts to a moving suspension member such as a lower control arm, while the rotary sensor body mounts to a fixed structure such as the frame rail.
As the suspension moves through travel, the sensor rotates through its range and reports actual position rather than inferred pressure. That gives the control system a much more accurate basis for leveling the truck and maintaining consistent ride height. The team highlights this as a more refined and reliable way to coordinate the airbags than simply trying to equalize PSI values.
Next, the discussion shifts to dampers, an area the presenter knows more formally. Because Fox acquired Ridetech several years ago, these shocks reflect combined development from both companies. The shocks selected for LockJaw are compact monotube units rather than the large bypass shocks associated with trophy trucks and prerunners, but the same core engineering principles apply.
The monotube design is preferred over a twin-tube layout for several reasons. In a monotube shock, the main body contains both the oil and the nitrogen, separated by a floating piston. The shaft carries a fixed piston with compression valving on one side and rebound valving on the other. Nitrogen is used instead of compressed air because it behaves more consistently across the temperature ranges encountered as the shock heats up in use.
Monotube construction also allows a larger piston and greater oil volume than a twin-tube design. In a twin-tube shock, one chamber sits inside another, which reduces the available size of the working oil chamber and piston. That reduction in piston area and oil volume can shorten service life and worsen thermal performance. By contrast, the monotube's oil is in direct contact with the outer body, allowing heat to dissipate more effectively to ambient air. The team expects that to improve durability.
These shocks also include external rebound adjustment via a knob at the top. That adjuster changes rebound valving so the damping can be tuned to the truck's exact needs. The combination of monotube architecture, larger piston area, better heat rejection, and adjustability makes the shocks a strong fit for a heavy custom truck that still needs refined suspension behavior.
The fuel system centers on Aeromotive components, chosen because the team has already pushed this hardware hard in other diesel applications. They specifically reference running Aeromotive brushless pumps at around 100 PSI on a Duramax while still maintaining substantial diesel flow. That combination of pressure and volume is not something every pump can deliver reliably, which is why they stayed with Aeromotive.
One of the key pieces is the fuel-pressure regulator. It uses large dash-12 inlet and outlet ports and is intended for very high flow. The regulator can cover a broad pressure range, roughly 30 to 120 PSI depending on the installed spring. Pressure is adjusted by changing spring preload through the upper cap, stud, and jam-nut arrangement. For this build, that wide range and high-flow capability are essential because the truck demands both substantial fuel volume and elevated pressure.
Filtration is handled by a very large post-filter assembly with dash-16 sizing and a 10-micron microglass element. The filter uses threaded caps so the internal element can be serviced. The team emphasizes pressure drop as a major design concern. In any fuel system, retaining as much pressure as possible from the pump outlet to the engine inlet improves performance and consistency. Large, low-restriction components like this filter, combined with short line routing, help minimize pressure loss through the system. The microglass media is also singled out as a preferred filtration material based on the team's prior data work in both fuel and oil applications.
The large Aeromotive fuel cell is another major packaging win because it eliminates the need to fabricate an aluminum tank from scratch. The presenter immediately comments on the weld quality, noting that aluminum is the most temperamental of the common fabrication metals compared with mild steel and stainless steel. The quality of the tank's welds leaves a strong impression, reinforcing confidence in the supplied assembly.
This is Aeromotive's largest fuel-cell package, a 20-gallon complete kit. It uses essentially the same pump family the team has run in dyno cells and on the Killing a Duramax project, where it supported just over 1,000 horsepower with room to go further. That prior experience is a major reason they trust it here.
Inside the tank, baffling is used to control fuel slosh and prevent fuel starvation during aggressive vehicle motion or as fuel level drops. That matters even though this is a truck build, because the team wants it to be genuinely drivable rather than a trailer-only showpiece. The 20-gallon capacity is specifically intended to support road trips to events rather than limit the truck to short local runs.
The pump itself is brushless, which the team strongly prefers over a brushed DC pump because brushless designs are more efficient and eliminate carbon brushes as a wear item. The tradeoff is that brushless pumps require electronic control, and Aeromotive addresses that with true variable-speed control. Using a 0-to-5-volt reference signal, potentially even from a throttle-position sensor, the controller can vary pump speed according to fuel demand. That means the pump does not have to run at full output while the engine is idling, which helps avoid unnecessary fuel heating. Aeromotive also supplied CAD data for the tank and related components, allowing the team to design brackets in SolidWorks, cut and bend them accurately, and expect proper fit on the first attempt.
Because the truck is intended for real road use, air conditioning is treated as a necessity rather than an afterthought. The team is using a Vintage Air universal system and begins by examining the firewall bulkhead fittings. These bulkheads are important because they create a clean, fixed pass-through point at the firewall, giving Sean at Empire Fab a defined area to build around in the engine bay. By anchoring the inboard and outboard A/C lines at one location, the installation should remain tidy and easier to package.
The kit includes the bulkhead, matching fittings, hoses, additional fittings, a pressure sensor, and the compressor. The compressor must be positioned on the engine and incorporated into the front-drive system, so mock-up is critical. The team wants to determine where it will live, what belt routing will be required, and how to keep it out of the way before the surrounding fabrication begins.
Under the dash, the truck will use a Vintage Air Magnum mock-up unit. During discussions with Vintage Air, the team learned that factory air conditioning was apparently a rare option on 1965-1966 trucks, so they plan to send the original dash vents to Vintage Air so a custom ducting kit can be developed. The mock-up unit is essentially an empty shell used to establish mounting position and packaging under the dashboard before the final functional unit is installed. In the finished system, that space would contain the blower, filtration, and ducting. The practical motivation is simple: the truck is expected to make long summer drives to events such as Lone Star Throwdown and Daytona Truck Meet, and those trips would be miserable without A/C in places like California, Texas, and Florida.
With the major suspension, fuel, and air-conditioning components now identified and partially unpacked, the next step is to begin physically locating them on the truck. There is still substantial mock-up work ahead, including bolting parts in place, checking clearances, and confirming how everything will coexist within the chassis and engine bay. None of that can proceed cleanly, however, until the body is removed from the original frame.
That sets up the next phase of the build: separating the truck body from its worn original chassis and moving it onto the new Roadster Shop frame. The team expects that process to involve cutting, penetrating oil, and a busy weekend in the shop. Once the body is on the new chassis, they can continue refining component placement and give Empire Fab the fixed geometry needed to begin the more complex fabrication work.