Myles Stocker’s 2006 Mazda V8-Powered MX-5 Miata

Myles Stocker knows cars. He’s built them, he’s raced them, and he’s restored them. Ask what he’s owned and modified, the list gets interesting– cars that include an AC Cobra, 1965 Mustang GT350R, 1956 Ford pickup with 392 Hemi, and 1961 Falcon Ranchero with straight axle and Holman Moody 289 hi-power engine. Oh, and then there’s the 1960 Ford convertible with 352 hi-power engine and 1961 Ford convertible with 375-horsepower 393 hi-power engine which he ended up swapping in a 427 tunnel-port and 4-speed. Some of those cars are from back when he was a drag racer for Ford, following his service in the Marine Corps.

It may strike you as odd to learn that he’s now driving a Mazda Miata. But this car has stayed true to the signature Myles modification ingenuity. “If you’re listening to the car, something’s not right. Doesn’t sound like a four-cylinder,” he said with a sly grin. Although the 2006 MX-5 looks bone-stock from the outside, lurking within is a GM Performance 425hp V8 crate engine, plus a Camaro independent rear suspension and TREMEC Magnum 6-speed transmission.

Darin Stocker fit a GM LS crate engine into this the 2006 Mazda Miata MX-5 and made it look like it came there from the factory.

“I’ve raced most of my life – mostly drag racing – then I left drag because you break too many parts,” Myles explained. “This is set up as a track car. The suspension is detuned and so is the motor a little bit. At track night, it’s extremely fast and very stable, but it’s not going to be an out-and-out race car. It’s my daily driver.” And those trips to the grocery store are always interesting, since the sleeper appears bone-stock from the exterior.

Adding to the cool factor is that the MX-5 was hand-built to perfection by his son, Darin, a fabricator and owner of DJT Motorsports, which specializes in road-race car preparation/fabrication and street-based hot rod builds. Although he started DJT Motorsports in 1985, it’s become a side business. Now, he’s  a Field Service Technicians for the DCT programs at TREMEC.

What’s the MX-5’s story?

Myles: It’s a Florida car. Not a scratch on it. Single owner. A 96,000-mile donor. When I bought the car from the guy, first thing after I paid for it, I said, “Do you want the motor, transmission, tires…I really don’t want them.” He asked, “Then why’d you buy the car?” When I told him what I was going to do, he said, “No way!”

Darin chose a TREMEC Magnum 6-speed for this build to create a powertrain that is powerful, reliable and versatile.

Why build a Miata this way?

Myles: I had a hunch. I’d seen articles about them and I mentioned the idea to my son and he said it would be no problem, so we went that way. I thought, that should be fun – I’ll go after Corvettes and other vehicles.

What modifications did you make?

Darin: I added a Chevrolet Performance LS376/480 crate mill, TREMEC Magnum 6-speed with close-ratio gear set – converted to 4th gen F-Body configuration – 2011 Chevy Camaro SS IRS fitted to the MX-5 subframe with 1LE 3.91 ring-and-pinion, and Mazda RX-8 hubs/uprights with Ohlins DFV coilover shocks at all four corners. There’s a Flyin’ Miata 2½-inch stainless steel dual exhaust with hi-flo catalytic convertors, resonators, x-pipe and mufflers, modified to fit Borla headers and the Camaro rearend.

The Chevrolet Performance LS376/480 crate engine produces 425 hp, giving the sport Miata an incredible power to weight ratio.

The front brakes are the V8 Roadsters 4-piston Wilwood 11.75-inch brake kit.At the back he did a V8 Roadsters 11.75 rotor upgrade. The 17×8 Kosei K5R wheels are paired to 235/40R-17 Yokohama S.drive tires. Inside, there’s a Sparco detachable steering wheel and seats, Dakota Digital gauges, rollbar and fire extinguisher mount from Blackbird Fabworx, Cadillac CTS-V gas pedal and pedal covers from Sullivan Racing Products for the brake and clutch, and Impact five-point safety harness belts.

The car makes 425 hp to the wheels and weighs 2,700 pounds. It still has ABS brakes and air conditioning.

Myles: The workmanship is really, really excellent.

Any challenges with this unique build?

The shift location on the TREMEC Magnum 6-speed is ideal for this engine and transmission swap.

Darin: The biggest challenge with projects like this is to make the installation look like it belongs in that space. I strive for an OE-looking installation, especially in the engine compartment. It was my first time working with this chassis, but nothing harder than any other project. I had help from V8 Roadsters – they had a front subframe available and other resources needed for this swap. Flyin’ Miata also helped with knowledge and some miscellaneous parts. The balance of the custom parts was created in-house at DJT Motorsports. I am a self-taught fabricator/mechanic who enjoys the odd build. The other build in the shop is a 2000 Mazda Miata with a Honda S2000 drivetrain.

The finished interior looks factory but includes a Sparco detachable steering wheel, Dakota Digital gauges and a TREMEC shifter ball atop a Hurst Billet/Plus 2 shifter and Flyin’ Miata T56 shift lever adapter.

Myles: I figured it would be straightforward except for the wiring since there are two computers: one is GM and one is Mazda. People say, “You could put that engine in that little car? It’s a nice fit. My son did an excellent job.”

What was the build process like?

Darin: DJT Motorsports touched every nut and bolt on this car. It took 3 years while I was working a full-time job at TREMEC.

Myles: I usually build my own cars, but I moved down to Florida 6 years ago and left all my tools in the shop and said, “They’re all yours.” We talked every weekend, and he would send me photos and video. I just let him take his time; I wasn’t in a big hurry. But you tend to get itchy and anxious toward the end, like with video of the car running. He’s very nerdy when it comes to work that has to be exact. He’ll redo it 20 times to make sure it feels right to him.

Wilwood 11.75-inch rotors at all corners with 4-piston calipers up front provide excellent braking for this lightweight car.

Why did you choose a TREMEC transmission?

Darin: The Magnum 6-speed transmission was designed around this engine – OE fit and function. This will handle the horsepower and live a long life. Don Walsh Jr. from TREMEC Elite Distributor D&D Performance in Michigan sold me the transmission and did the dyno tuning on the engine.

Myles: The main reason I chose a 6-speed is because of the double-overdrive. Even with this horsepower and gearing, I should still be able to get 20 mpg. Darin worked out the car’s gear ratios.

The trunk has the battery and two charging posts, and there are also two hidden kill switches.

What kind of shifter did you choose?


Darin: Hurst Billet/Plus 2 shifter and Flyin’ Miata T56 shift lever adapter with black TREMEC shift ball.