See How Cool Hand Customs Revived and Hemi-fied a 1974 Plymouth Duster

Amy and EJ Fitzgerald of Cool Hand Customs weren’t the first to stuff a Gen III Hemi in a Plymouth Duster. That didn’t stop them from building their version by swapping the drivetrain from a 2007 Chrysler 300 SRT8 into a 1974 Duster and making it look like the Plymouth factory put it there. Amy and EJ then built the rest of the car Pro Touring-style to complement the Hemi’s horsepower chops.

You can hear all about the build in this Summit Racing YouTube video, and see the parts Amy and EJ used in our Cool Hand Customs 1974 Plymouth Hemi Duster Parts Combos.

Engine Upgrade Parts
The SRT8’s 6.1L Hemi is rated at 425 horsepower and 420 lbs.-ft. of torque in stock form, which is plenty for the lightweight Duster. Cool Hand Customs kept the engine much as Mother Mopar built it. They replaced the oil pan with a Milodon Street/Strip pan designed to fit a Gen III Hemi in Mopar A- and B-body vehicles. EJ fabricated a set of 1.75 inch primary long-tube headers using a Summit Racing™ Weld-Up Header Kit for a small block Chevy and a pair of Stainless Works header flanges. The headers connect to a custom 2.5 inch stainless steel dual exhaust fitted with a pair of Flowmaster FlowFX stainless mufflers. The exhaust exits just in front of the rear tires.

Cool Hand Customs chose to use a Holley Terminator X MAX engine management system to keep the Hemi humming. Designed for Gen III Hemi engine swaps, the Terminator X MAX is self-learning and is loaded with base tuning maps to get the engine up and running quickly, and also allows full access for creating custom tuning. It comes with a one-bar MAP sensor plus boost and nitrous controls if you want to add nitrous or a turbo.

The Hemi gets its gasoline from a fuel system based on a Tanks Inc. fuel tank and a Summit Racing™ Universal LS-Style Fuel Filter/Regulator. A direct replacement for the factory tank, the 16 gallon steel tank is fitted with a 255 LPH electric fuel pump and sending unit. The Summit Racing filter/regulator is rated at 58 PSI and has a five-micron filter. The unit’s compact size makes it ideal for EFI engine swaps in classic vehicles.

Suspension System
Amy and EJ turned to the handling experts at QA1 for the suspension. The front suspension features tubular upper and lower control arms with polyurethane bushings and additional caster for better handling; Stocker Star twin-tube shocks that are fully adjustable for compression and rebound; a tubular steel K-member that provides additional clearance for headers and oil pans; adjustable strut bars to eliminate suspension bind for faster weight transfer; and a 1.25 inch diameter chromoly steel sway bar.

Cool Hand replaced the Duster’s leaf spring rear suspension with a QA1 six-link coilover shock suspension. That kit is no longer available, so we included QA1’s triangulated four-link coilover kit. It features adjustable upper lower trailing arms; adjustable lower trailing arms that let you set the wheelbase to fit bigger tires; and double-adjustable coilover shocks. The kit provides clearance for three inch diameter, over-the-axle exhaust systems, and can be used on cars with standard spring locations or with an inboard spring conversion to fit bigger tires. This QA1 video goes into more detail on the four-link kit.

Chassis and Front Brakes
Cool Hand Customs replaced the Duster’s original tie rod ends, pitman arm, and idler arm with Moog replacement parts, and converted to power steering with a Borgeson conversion kit. They also converted the front brakes from manual drum to power disc. Our combo includes a Classic Performance power front disc brake kit with 11 inch diameter solid rotors, black powdercoated single-piston calipers with pads, stock-height spindles, and a master cylinder/eight inch brake booster assembly. It also includes upper control arms and ball joints which you won’t need if you go with the QA1 front suspension.

Cool Hand Customs also replaced the Duster’s 8.25 inch rear axle with a Moser Muscle Pak 8.75 inch axle assembly with a 3.73 ratio gear set, a Trutrac limited slip, 33-spline axles, and 11 inch disc brakes. You can special-order one from Summit Racing for your own A-body project.

Body Restoration Parts
The Duster needed some sheetmetal replacement and removal of the dents and dings a car accumulates over almost five decades. An Auto Metal Direct trunk pan and trunk extensions took care of the trunk issues, and the quarter panels were brought back to life with Goodmark lower quarter patches. Cool Hand also replaced the windshield and backlight with Auto Metal Direct tinted glass, and swapped the factory sheetmetal for the front end from a 1967 Plymouth Valiant.

Interior Parts
Cool Hand Customs went all-out on the Duster’s interior. Since the transmission tunnel had to be modified to clear the big NAG1 five-speed automatic from the SRT8, the factory front split-bench seat would no longer fit. It was replaced with TMI Pro-Series black vinyl bucket seats with contrasting orange stitching. TMI also supplied Sport Series door panels and rear quarter panels that match the Pro-Series seats, and the rear bench was recovered in black vinyl. A custom-built center console houses the Autostick shifter from the donor Chrysler 300C.

The Duster’s dashboard was smoothed and fitted with a Holley EFI Digital Dash and a VDO fuel level gauge. Designed to work with Holley EFI systems, the EFI Digital Dash monitors engine functions in a customizable display, and also has a virtual switch panel that eliminates the need for physical switches for headlights, turn signals, etc. That’s pretty slick.

A Flaming River tilt steering column is topped with a leather-wrapped Grant Collector’s Edition steering wheel. The wheel comes in black, but Cool Hand talked Grant into adding orange stitching to match the rest of the interior. SafTBoy seat belts keep driver and passengers in place when they’re hustling the Duster through the twisties on the way to the Dairy Queen.

Coatings
Cool Hand Customs uses KBS products on all of its project vehicles, and the Duster was no exception. Here’s the list:
• Klean Surface Cleaner
• RustBlast Rust Remover
• RustSeal Rust Preventative Coating
• Blacktop Chassis Coating
• Top Coater Paint
• Undercoat Rubberized Undercoating
• Motor Coater Engine Enamel, black and orange
• Xtreme Temperature Zinc Primer
• Xtreme Temperature Coating, aluminum

Cool Hand also had KBS custom-mix a batch of its MAXX Orange Crush single-stage paint to their specifications. According to Amy, the paint was so hard, they spent more time color-sanding and buffing it than any other paint job they’ve ever sprayed.

Electrical System
Amy and EJ rewired the Duster with a Painless Performance universal 21-circuit harness to get the electrons where they need to go to activate the Duster’s lighting, starter, alternator, and ignition, electric fuel pump, and other electrical doodads. They also tapped Painless Performance for electric fan and fuel pump wiring relays; a battery cable kit; a headlight plug harness; and a brake light switch.

Holley provided a gauge power harness; a GPS sender module for the speedometer on the Holley EFI Digital Dash; an ignition coil adapter harness; and a USB cable to connect the Terminator X MAX engine management system to a laptop computer.

CHECK OUT THE COOL HAND CUSTOMS HEMI DUSTER PARTS