For many, the Holden Gemini was a simple stepping stone to supposedly greater things – a first car loved and tinkered with, but ultimately replaced by something with more cylinders and more power. Not for Mick Khodr – his built TX Gemini smashes quarters and hoovers up trophies in equal measure, rocking genuine, force-fed Isuzu power.

First published in the February 2026 issue of Street Machine

It’s astounding how few Geminis are out in the wild these days, especially considering it was one of Australia’s highest-selling cars during its 10-year stint on the market from the mid-70s to mid-80s. As a popular first-car choice for many young Aussies back then, they were frequently used and abused, and even those that avoided such treatment still had two major foibles in the form of a problem-prone head gasket and an almost heroic penchant for rust.

Mick hasn’t avoided either of those pitfalls during his Gemini journey, which began way back in the early 1990s. “My brother had a TD Gemini sedan with the customary 32/36 Weber, extractors and exhaust,” he says. “He bought the first Holden in our family; the rest of them had XB and XC Falcons. It really planted the seed for the humble Gemini, and Mum’s last car before she passed was a TG, so that sealed the deal.”

Mick scored himself a late-model sedan for only $400 with – you guessed it – a blown head gasket. “I ended up stripping the motor and completing a full rebuild with a ported head and a big cam,” he says. The built motor fixed one of the Gem’s inherent issues, but the other quickly became evident. “One day I closed the passenger door and the sill disintegrated,” Mick laughs. “So, I pulled out that fresh motor and scrapped the rusty shell.”

Mick’s nice little naturally aspirated mill went into another TG, and it became his dependable daily driver for a couple of years, ticking off over 700km a week between home, work, and uni.

But Mick had big plans for his Gemini, so in 2004, he pulled it off the road. “I was going to turbo the existing 1.6-litre, but I sold it to my mate Matt Jones instead,” he says. “Then I was going to go rotary, but eventually I settled on big-block Isuzu power – by that I mean the 2.6-litre 4ZE1 from the TF Rodeo.”

The Rodeo motor was stripped and sent off for machine work, gaining a set of custom forged pistons, shot-peened rods, O-ringed block, and a copper head gasket sandwiched between the bottom end and the ported SOHC head. “I upped the valve springs and got Watson Racing Cams to grind me up a mild turbo cam,” Mick explains. “Then it sat on an engine stand waiting for the bodywork to be completed on the TG.”

Unfortunately, upon the car’s return, Mick realised the bodywork wasn’t at the standards he was expecting. “I’m a bit obsessive-compulsive, but my brother also told me, ‘Do something once and do it right.’ This car wasn’t right, so I sold it,” he shrugs.

Life took over and Mick’s Gemini project was unofficially put on hold, but his dream of building the ultimate Gem never died. “I always wanted a coupe, but I couldn’t find the right one,” he says. During his search, Mick still had the motor in his garage, turning it over by hand every couple of months to remind himself that it was ready and waiting for the right engine bay. Finally, in late 2012, it appeared.

“I saw this shell for sale in Queensland; it was already painted BMW Black Sapphire and came with a few spares,” Mick says. “I thought it would allow me to revive the project and expedite its completion, so I flew up there and it looked good. I brought it home, and my brother came over. He’s a panel beater and pointed out some flaws and potential problems.”

Mick is understating things a tad, as his brother jabbed his keys into the quarter panel, dislodging a heap of poorly applied filler. “That sealed my fate for the next 10 years,” he says, “but I couldn’t start again. I had the shell, so I had to heed my brother’s word to do it once and do it right.”

As any customiser will know, doing it right in the 21st century isn’t just a matter of quality workmanship; there’s also the need for compliance, as nobody wants a yellow sticker on the window. “I got in touch with an engineer, who advised me my 2.6-litre engine wouldn’t be acceptable with a turbo,” Mick sighs. “So, I sourced a 2.3-litre 4ZD1 – they’re a lot harder to find – and decided that if those extra 300cc were a problem on paper, I’d better make sure it made more power.”

The 2255cc, SOHC, petrol 4ZD1 four-banger was available in the first-gen Holden Rodeo from its July 1985 facelift though to August 1988. It was far from a sporty engine, but Mick’s rebuild sorted all that. The 2.6 4ZE1 was sent to Advanced Performance Machining in Smeaton Grange for a complete tear-down and transfer of some of the internals into the 2.3-litre block. “I wanted to use the bigger stroke to help spool the big turbo. We made it all work using custom rods and pistons, and I had the valvetrain redone on the ported head I’d built for the 4ZE1,” Mick explains.

Between the ported head and 4ZD1 block, APM inserted a custom-cut copper gasket able to handle a whopping 45psi of boost, and up above all that, Sure Cam created a bumpstick that allows the truck motor to smash through to 8000rpm, yielding plenty of power and torque in return. Naturally, to get an old Isuzu to spin that hard with only one cam, the whole lot was balanced and blueprinted, and then a bloody big BorgWarner S257SX-E twin-scroll turbo was strapped to the side.

Mick spent another two-and-a-half years assembling and finalising the build, with huge help from none other than Matt Jones, with whom he’d lost contact and reconnected with in the intervening years. “Matt was a huge help and support,” Mick says. “He did a phenomenal job on the body, taking it back to bare metal, cutting out all the rust and spending months getting it perfectly straight.” Matt also gapped the body to within an inch of its life (3/16ths of an inch, actually), with the aim of a Summernats Top 60 gong in the near future. “He also stored the car, and together we finished the fuel system and suspension, rebuilding or refurbishing every bit along the way.”

What Mick’s words don’t convey is just how bespoke almost every part of the build had to be. Gemini stuff is out there, but not dyno-smashing, low-10sec-craving Gemini stuff. As vindication of Mick’s OCD, however, every part of the car is as presentable as it is functional. Except, of course, for that interior; that’s just art: “I shouldn’t say this, but it’s my favourite part of the car,” Mick admits.

It’s a fair statement; you can love the boosty-boi Isuzu engine, you can love the body and paint, but it’s the dashboard that you see the most and the seats where you plant your bum – something Mick is planning to do a lot more of now his ultimate Gemini is done.

MICHAEL KHODR
1975 HOLDEN TX GEMINI SL COUPE

THANKS
My family; Matt ‘Dr’ Jones; Jonathan Tapia at Macarthur Autobody; Simon at Seamsright Auto & Marine Upholstery; Steve at Sparks Auto; Starsi at BBSfab & Performance; Jason Lowe for the powdercoating; Craig at CAD Automotive Paint Correction; Scott and Adam at Ichiban; Chris Spicer; Paul at Cortya’s Metal Polishing; Tony Lattuga; Adam Warwar; Mohammed Jamus; Dave Cox; Scott Forrester; Luke Cranks; Sam Battiato; Paul Dingeldei; Corey Gould.