Classic Cars and Rides

Mercedes W123 300D 1JZ Swap – 420hp Bagged Build

Mark Ratana’s unique 1985 Mercedes W123 300D with a 1JZ-GTE swap, 420hp, air suspension, and custom fabrication—an old-school diesel turned street legend.

Mr2mivin

Mercedes W123 300D 1JZ Swap – 420hp Bagged Build

Bagged Mercedes W123 300D 1JZ Swap

TL;DR – Key Takeaways

Mark Ratana transformed a classic Mercedes W123 300D into a 420hp street machine with a Toyota 1JZ-GTE swap.
The build features a mix of Driftmotion performance parts, Haltech management, and custom fabrication.
More than just a car, this project embodies authentic car culture, blending old-school Mercedes charm with JDM reliability and boost.

Mark Ratana

1985 W123 Mercedes Benz 300D

Instagram: @W123GTE

Photographer: Marvin Recinos

Instagram: @Mr2mivin

Performance Stats:420hp

From Bangkok to Los Angeles – A Car Enthusiast’s Journey

“My name is Mark Ratana, I’m 42 years old, and cars have been part of my life for as long as I can remember.” That’s how Mark begins his story, one rooted in both nostalgia and passion. Born in Los Angeles but raised in Bangkok, Thailand, he grew up immersed in automotive culture in two very different worlds.

Like many ‘90s kids, Mark’s earliest obsession wasn’t with full-size cars but with Tamiya battery-powered track cars. In Thailand, those pocket-sized racers were a craze—customizable, competitive, and endlessly fun. It wasn’t just about speed; it was about learning how a few tweaks—removing a part here, adding one there—changed performance. That same spirit of tinkering carried into his first real car. From then on, Mark never kept anything stock.

When he and his wife moved back to Los Angeles in 2014, the California car scene reignited his passion. But with strict emissions laws, owning a modified Subaru STI came with headaches. Despite running full bolt-ons, Mark found himself parked more often than driving—after collecting two dreaded state ref tickets. That frustration sparked a thought: what if I could build something fun, powerful, and still street-legal?

1985 W123 Mercedes Benz 300D

Why a W123 Mercedes-Benz 300D?

That’s where the 1985 Mercedes-Benz 300D W123 comes in. Old-school diesels like the W123 are smog exempt in California, meaning they provide a rare loophole for modifiers. To Mark, that made it the perfect canvas—something he could push to extremes without worrying about red tape.

But Mark didn’t just want a classic Benz cruiser. He wanted a build that would shock people when they looked under the hood. Instead of keeping the original diesel setup, he swapped in a Toyota 1JZ-GTE VVTi. Known for its bulletproof reliability and legendary inline-six sound, the 1JZ brought JDM flavor to a European icon.

“It’s not something anyone expects to see,” Mark admits. “You pop the hood of a 40+ year old Benz, and there’s a 1JZ staring back at you. The reactions are priceless.”

Performance and Fabrication – The 420hp Setup

This isn’t just an engine swap—it’s a full performance build, carefully pieced together with Driftmotion components, Haltech management, and custom fabrication.

Engine and Drivetrain

Mark’s 1JZ is equipped with:

ARP head studs for reliability
Driftmotion 6262 Ball Bearing Turbo kit
Fluid Damper and Non-Stop Tuning pulley kit
Injector Dynamics 1050x injectors with a Radium fuel system
Haltech ECU and digital dash
R154 transmission paired with a Driftmotion Stage 4 clutch and flywheel
Lexus SC300 rear differential with a CBS Racing Helical LSD

At full boost, the setup produces around 420hp at the wheels, a staggering figure for a platform once known for slow, smoke-belching diesel pulls.

Suspension and Handling

To modernize the ride, Mark runs Maxload air suspension with Accuair height sensors, paired with Nissan S13 rack and pinion steering and GK Tech tierods for sharper response.

Wheels and Brakes

The stance is completed with Maxilite Penta-style wheels (17x8 front, 17x9 rear) wrapped around upgraded Mercedes W126 front brakes with EBC Red Stuff pads.

Custom Fabrication

Mark takes pride in doing most of the fabrication himself, from fitting the axles to fabricating solutions for discontinued Mercedes parts. When things break, he doesn’t order replacements—he makes them work. That DIY ethos makes this build even more personal.

1985 W123 Mercedes Benz 300D

The Driving Experience

Despite the challenges, the car has been a joy. Mark takes it to local meets, where it always sparks conversations. It’s equally at home cruising through LA canyons as it is parked at a Cars and Coffee.

“It’s not perfect—sometimes things break, and I’ve had a few late-night tow truck rides. But that’s the beauty of owning a car like this. You learn, you adapt, you fabricate. That’s what makes it fun.”

For Mark, the 1JZ-swapped W123 isn’t just transportation; it’s a bridge between past and present, between his childhood love of modifying and his grown-up vision of building something unique.

Build List Recap

Engine: Toyota 1JZ-GTE VVTi, ARP head studs, Driftmotion 6262 turbo kit, Haltech ECU & dash
Fuel & Intake: Injector Dynamics 1050x, Radium fuel system, AEM pump, PMAS intake
Drivetrain: R154 transmission, Driftmotion clutch/flywheel, Lexus SC300 diff, CBS Helical LSD
Suspension: Maxload air suspension, Accuair height sensors, Nissan S13 rack & pinion
Brakes & Wheels: Mercedes W126 front brakes, EBC pads, Maxilite Penta wheels 17x8 / 17x9

Future Plans

Mark isn’t finished. The next step? Possibly a bigger turbo and cams, pushing the build into even wilder territory while maintaining that sleeper Benz vibe.

Shout Outs

@projectcollier – engine rebuild, wiring, tuning
Photographer: Marvin Recinos (@mr2mivin)
Friends and family who support the late nights in the garage

1985 W123 Mercedes Benz 300D engine bay with 2jz engine

Dream Car

Even after building one of the most unique W123s around, Mark has another dream: a Nissan R32 GT-R or an A80 Toyota Supra. If his current build is any indication, those won’t stay stock for long either.

Magazines On Amazon

Call to Action

Do you have a build story like this one? Got a build on a budget? We want to see it. Submit your story to Stance Auto Magazine, and you could be the next featured owner showing the world how to do it right—without breaking the bank.

And hey, don’t forget to tag us on socials. Use #stanceautomag on Instagram, Pinterest and Facebook so we can see (and maybe feature) your ride.

Test Your JDM Car Knowledge and Take Our No. 1 JDM Car Quiz