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Big-block pro street 1937 Plymouth coupe

By Simon Major | Photos: Ellen Dewar, 24 Oct 2019 Features

Big-block pro street 1937 Plymouth coupe

Inspired by a father's memory and a love of pro street styling, Dean Wilson created the ultimate show-and-go Plymouth coupe

INSPIRATION for a project can often be as diverse as the finished product, with elements that sometimes combine to take this process full circle.

This article was first published in Street Machine's Hot Rod magazine #20, 2019

Plymouth coupe rear

House of Kolor Deep Cherry Kandy hue bounces from burgundy to crazy shades of plum, purple, red and black depending on the light. “Dad loved orange cars and was toying with different shades for the coupe, but I’d always rib him and say it was going to look like a taxi,” Dean laughs. “So I had to stick to my ‘no-orange’ guns.” The Billet Specialties Win Lite rims tie in perfectly with the pro street essence of the build, and the ‘MYDADS’ plates are on point

Brisbane’s Dean Wilson is a case in point. He built this strikingly tough Plymouth Coupe in memory of his late father, Errol – who’d originally started the build of the ’37 more than a decade ago – but also drew on his own love for pro street hot rods, which dates back to when Errol first took him to the Valla Park Hot Rod Run.

Plymouth coupe rear

“I was four or five when Dad took me to Valla,” Dean says. “And the ‘34 coupe of Fred Cavasinni and Willys of Norm Longfield just blew my mind.”

Read next: Dean's Plymouth makes the Super Six at MotorEx 2019

Plymouth coupe

Dean’s Plymouth is a beautiful shape from the factory but has been refined with a lengthened nosecone and front guards amongst myriad nips and tucks

Fast-forward to 2001, and Errol was keen for a new project. Aiming for something different to the more common Ford-based rods, he sourced this 1937 Plymouth from Melbourne as a freshly landed Californian import. Errol tinkered away on the Mopar for the next eight years, getting it to mock-up stage with a Mitsubishi L300 front end, 360 Chrysler donk and nine-inch combo, and the body pretty much ready for paint.

Read next: Mario Colalillo's 1000hp 1939 Plymouth coupe

Plymouth coupe front

“Dad was famously slow for doing things but was in the home stretch,” says Dean. “He was toying around with different shades of orange in preparation for the final push, but it was at this stage in 2009 that he died suddenly following a heart attack.”

Dean stepped up to finish the project and drew on skills learnt both as a fitter and turner and through building his own ’34 Chev tudor to take Errol’s Plymouth to the next level. Work recommenced in 2015 and four years later the car was finally deemed ‘finished’, having been seriously transformed in both the show and go departments.

Read next: 383-cube 1941 Willys coupe

Plymouth coupe at Motorex

“I’ve always loved tough cars, and, whereas my mates have cool street machines, I am a hot rodder at heart,” says Dean. “My tudor will run 10.80s all day, which is cool, but this time ’round I decided to get serious and focus on a proper pro street build, you know, like the style of the cars that made my jaw drop as a young fella.”

With that in mind, the Plymouth was stripped bare and rejigged to better follow Dean’s vision. The boxed chassis rails were modified with new crossmembers and hollows to route the planned exhaust system, whilst the once-traditional L300 front end was swapped out for a complete Rod-Tech independent unit that incorporates power rack-and-pinion steering.

Read next: Tail dragging 1936 Ford coupe

Plymouth coupe tail light

Errol’s original plan called for a nine-inch rear, which Dean retained, albeit stepped up to a Strange housing equipped with Altra 9 35-spline axles and fully floating hubs. This assembly was located using a four-bar system, McDonald Bros panhard bar and Gazzard dual-adjustable coil-over shocks.

“I wanted to go quick so spent the money on the good gear straight up – the tipping point for the build was right at the start but I just didn’t realise it!” Dean laughs.

Plymouth coupe wheel

Don’t let the purists sway you – mixing breeds is at the core of hot rodding’s identity, so Dean had no hesitation to swap out the Mopar-matching 360 donk for some big-block Chev goodness, ably screwed together by Kev Morton at KPM Performance.

Four-fifty-four has such a gloriously iconic ring to it, and forms the cubic capacity of the Dart Big M block swinging a Callies billet crank and Oliver rods. Gas port JE pistons were selected for the planned nitrous hit, whilst a billet Moroso oil pump and gated, baffled alloy sump both keep the juices flowing at times of need and button up the short assembly.

Plymouth coupe engine bay

The 454-cube big-block Chev mill is based on a Dart Big M block and was expertly built by Kev Morton at KPM Performance. Twin throttlebodies are whopping 2000cfm Holley items atop a sheet metal Bain Racing intake, but the 1250cc injectors ran out of legs during an NA 947hp run on the engine dyno! The nitrous system is locked and loaded, ready for Dean’s planned drag strip action

A solid-roller camshaft ground to 280-degrees duration and .800-inch lift forms the basis for the valvetrain, with Morel lifters working north towards shaft-mount T&D rockers and PAC Racing valve springs housed in Dart 360cc alloy heads. A Bain Racing sheet metal intake connects the cylinder banks and is topped by a pair of whopping 2000cfm Holley throttlebodies. These are matched with a generous supply of E85 via a set of 1250cc injectors sourced from a Dean-made 115-litre fuel tank that features a pair of internal 1000hp Aeromotive pumps.

Plymouth coupe engine bayA 7AL-3 ignition control, front drive distributor and leads are all from the MSD catalogue, while the Dean-fabbed exhaust features 2.25-inch primary headers that flow into a twin 3.5-inch stainless system.

A Holley Dominator ECU is the brains of the operation, which also features a tailshaft sensor traction control system and provision for multiple tunes for street or race action.

Plymouth coupe engine“It made 947hp naturally aspirated on the engine dyno but ran out of injector, so once that’s sorted I’m hoping for 1000rwhp with a 200 shot of gas,” Dean says. “I’m hoping to run in the 9.30s but can step up to 500hp pills as I get a handle on how the car will behave.”

Plymouth coupe engine bayStout figures in anyone’s language, but a non-event if you can’t reliably get the power down, so the rat donk is backed by a Reid-cased, full manual Turbo 400 featuring a reverse-pattern shift and transbrake, fronted by a 4500-stall billet convertor. The aforementioned nine-inch runs Wavetrac 3.7 gears and an alloy centre, while braking duties are handled by a complete Wilwood package that features an underdash master cylinder actioning drilled and slotted rotors at each corner via four-piston calipers. Wheels are a mix of 17x4.5- and 15x10-inch Billet Specialties Win Lite, wrapped in Mickey Thompson rubber.

Plymouth coupe interior

The black-based interior draws on elements of both street and race, with all upholstery work completed by North Coast Custom Trim. The custom centre console houses the handbrake, TCI shifter, transbrake and – yep, you’re seeing right – a pair of cup holders

Ample amounts of ‘go’ has been well sorted, but Dean also had the ‘show’ angle nutted out at an early stage.

“I quickly realised there was no point putting all of this coin and quality running gear into a shitter, so stepped up the rest of the build to suit,” he says.

Plymouth coupe seats

The door glass is now quarter vent-delete and features electric operation for added cool. An Ididit steering column and Billet Specialties twirler work in nicely with the Simpson race harnesses and body colour ’cage 

To that end, the five-window body was channeled two inches to balance Dean’s desire for a low stance and extra real estate to house the driveline and exhaust, while the front fenders and nosecone were lengthened and reshaped to improve their proportions. The bonnet has been converted from four-piece operation into three, while a custom billet grille was sourced from the US to further personalise the coupe’s look.

Plymouth coupe gaugesThe talents of Paul Cundy and David Athans were sought to weave their magic over the Plymouth’s panel and paint, and the resulting ultra-perfect bodywork flowed with Deep Cherry Kandy from the HOK charts is testament to their skills.

North Coast Custom Trim were tasked with the interior makeover, wrapping Honda front bucket seats in black leather matched to black Mercedes carpet and a one-piece suede headlining. Street-worthy fast glass, an Ididit steering column, Billet Specialties steering wheel and custom console mix with the race-spec Autometer gauges and six-point chrome-moly rollcage, the latter of which is teched to 8.00-second passes and removable should the need arise.

Plymouth coupe console

The accolades came thick and fast following the Plymouth’s Summernats 32 unveil and Super Six Finalist berth at MotorEx, however, being awarded Top Hot Rod at the Maryborough Street Rod Nationals at Easter held a particular resonance.

“The Maryborough weekend was also the 10th anniversary of Dad’s passing, which made the win even more important,” Dean says. “He would be over the moon at just how far his old hot rod has come.”

Dean WilsonDEAN WILSON
1937 PLYMOUTH COUPE

Paint: HOK Deep Cherry

ENGINE
Engine: 454ci Chevrolet big-block
Block: Dart Big M
Crank: Callies billet
Conrods: Oliver I-beam
Pistons: Gas ported JE
Camshaft: Solid-roller, 280-degree duration, .800in lift
Intake: Bain Racing
Throttlebodies: Twin 2000cfm Holley Dominator EFI
Heads: Dart alloy
Lifters: Morel Black Mamba
Rockers: T&D shaft-mount
Fuel pump: Twin 1000hp Aeromotive
ECU: Holley Dominator
Exhaust: 2.25in primary headers, dual 3.5in stainless system
Ignition: MSD 7AL-3 ignition, MSD front-mount distributor, MSD leads

TRANSMISSION
Transmission: Turbo 400, full manual reverse-pattern valve body
Convertor: Billet 4500-stall
Diff: 9in, Wavetrac 3.7:1, Altra 9 35-spline axles, full-floating hubs

SUSPENSION & BRAKES
Front: Rod-Tech IFS
Rear: 4-bar, McDonald Bros panhard rod
Shocks: Rod-Tech (f), Gazzard (r)
Brakes: Wilwood discs (f & r), Wilwood master cylinder
Steering: Rod-Tech power rack-and-pinion

WHEELS & TYRES
Rims: Billet Specialties Win Lite; 17x4.5in (f), 15x10in (r)
Tyres: M/T Sportsman 17x6in (f), M/T ET Streets 275/60 (r)

THANKS
My stepmum Lynn Scheuber for giving me the car; Lawrie Scheuber & Craig Fischer for help throughout the build; Kev Morton and KPM Performance for the engine build and tuning; Paul Cundy and David Athans for bodywork and paint; Steve Falzon and Kev Morton for electrical wiring; Chris Pitcher and Mason Cahill for always being there to help when needed; last but definitely not least, my better half Lydia Stewart for all of the running around getting parts and putting up with the crazy build

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