Corvette Craft: The Story Behind GTS Customs

GTSCUSTOMSSHOP_LEADART_1To say that Southern California is a haven for automotive enthusiasts is an understatement. Out here, you’ll find countless shops, stores, businesses, and organizations dedicated to the machines that move mankind. The inhabitants of this region may suffer some of the most stringent red tape when it comes to governmental regulations, but they get by living on their passions, whether it be 4x4s, hot rods, imports, muscle cars, or the like.

REWA_160For Greg Thurmond, owner and founder of GTS Customs, the reason for existence, is to give the Corvettes of years’ past an absolute makeover, making them more worthy of the nimble, performance-minded mantle ascribed to more recent models like the C5, C6, and C7. It’s a challenging, high-wire act on each and every car, requiring the utmost respect for the silhouette with a desire to enhance the skill, but Thurmond likes it that way.

The man’s shop occupies a rather innocent yet ironic space on Easy Street in Simi Valley, advertising itself as Outrageous Paint to the unknowing passerby. The folks that do recognize GTS Customs, however, are savvy and well-financed enough to know what they want while giving Thurmond the space–and time–needed to do the job right. And Thurmond is nothing if not focused on having everything done to a “T,” as we learned in our interview.

REWA_001The Man, The Shop, And The Passion

Corvette Online: How long have you been set up here with GTS Customs?

Greg Thurmond: I’ve been here in Simi Valley since 2000, but before that I was in Chatsworth since 1987.

REWA_089CO: And were you born into this business, or what is your background?

GT: My background is I was born in Torrance, California. I grew up in San Fernando Valley, Canoga Park to be exact, and moved to Simi when I was–let’s see–been out here since ’99, I think.

CO: What did your dad and mom do for a living?

GT: My dad was a mechanical engineer, and my mom was a housewife. My dad had a hobby of restoring cars, and bought a nearby auto upholstery business, called Canoga Park Auto Tops. The year was 1971 and I was about 12 years old when we got that shop, and that’s how I started hanging around cars.

CO: At what point did you get to Chatsworth?

GT: 1987, I was 28 or 29 at the time and had built up enough experience and confidence to go into legitimate business for myself. I just did anything back in those days–a lot of collision work. People would bring me a lot of collision work on their vehicle, but I always had one or two Vettes in the shop there too. I was either building my pride and joy, a ZR1, or bringing one back from the dead.


Various odds and ends are placed on a hole-punched board.

CO: When did you get set up here in Simi Valley?

REWA_141GT: I moved here in 1999. I had operated a business in Chatsworth called Outrageous Detail, but I was essentially hustled out of there thanks to L.A. County officials. I also started focusing a lot more on Corvettes–always did a lot of them, and it was my hobby to tinker with them, going all the way back to when I built one at 17. So at this point, I just had enough jobs coming along to where I could say, “Okay, I can turn away the other stuff.” Nowadays, I’d say about 80 percent of the work I do is exclusively Corvette-related.

CO: How many would you say you’ve completed since opening up shop here?

GT: I’ve been doing this for fifteen years, and I’ve since completed 35 Corvettes.

CO: Wow. You must really take your time with these projects then.


One of Thurmond’s greatest achievements was his “Retrovette,” a C1 that he restomodded back in 1998.

GT: Oh, yeah. Everything is covered. Every detail.

CO: What does the typical Corvette look like when it comes into the shop?

GT: Typically, they aren’t pretty. We get the paint off of them and find the front ends look like crap; bonded up and done poorly. Thus, we usually have to remove the front end and replace it. Sometimes the rear end too. We make and install wider quarter panels for the Vettes C1’s and C2’s.

CO: So you tuck a bigger tire under there?

GT: Yeah. Makes the car look stock, but it adds an inch and a half more wheel clearance. That’s part of what makes us special.


It’s the little things that keep you going…

CO: So what is it that you like best about Corvettes? They seem to have a very deep connection with you.

GT: Yeah, you know it’s all about the performance I guess. As I worked on them, I noticed early on everything on a Vette was like beefier and better and stronger than on a Camaro. Now I knew Camaros and I knew Vettes so you could see all the differences GM made to make the Vette better, you know. More pistons in the brakes, fiberglass panels to save weight, all that kind of stuff.


…we’re talking about the energy-restoring snacks, of course!

CO: You care a lot about the history and lineage of the Corvette so how do you balance the restomod aspect while keeping the original character intact?

GT: Carefully. Yeah you gotta steer people away from making major modifications that are gonna turn it into an ugly piece of junk. There are certain modifications that even I won’t do.

CO: How long does the process take and how much is the price range?

GT: Depends on the customer and generation of Corvette. Most of our work is resto-modding the drivetrain and interior. The process takes from one to two years and will run up to about $125,000 minimum. And for C1s, a minimum now of about $175,000. But that’s including a Newman Car Creations chassis which is over $50,000. So right off the bat you just spend 50 grand when the chassis rolls in here. As for the length of time required, it’s a matter of getting everything right, and that’ll take us one to two years to do these things.

REWA_187CO: So you build parts here, correct?

GT: Well, we develop the parts here, and now I actually have a fiberglass production facility that I sublet the manufacturing part of my fenders to. He has my molds.

CO: And do you also have molds for other generations?

GT: The C2 we have, so we cover all the midyears with one fender. The C2 fender is one inch wider and the C1 fenders are one and a half inch wider, giving additional wheel clearance for performance reasons.


This 1959 model belongs to an owner up in Ontario. Per the Newman chassis installation, it’s also received an LS3 motor and T56 transmission.

What’s In The Shop

Spanning the dual suites that make up GTS Customs were a total of six vehicles, five of them early model Corvettes. Here, we had a cherry 1959 C1 running an LS3 engine with T56 Magnum six-speed transmission and Dana 44 rear end. “This is a straightforward, simple build,” said Thurmond. “Just upgraded drivetrain and suspension, to make it better for daily driving.”


After a year and a half of work, this car will be heading back to its owner very soon.

The car had undergone close to 1,500 hours of work time, after having been at the shop for nearly a year and a half, and is planned to be shipped to its home in Ontario in November.

Another Corvette, this one a white split-window C2, was dissected into three spots inside the shop. Nearest the back wall, there lay all the chassis and related components sitting in an arranged pile according to where they would wind up.” So basically this car was all put together ’cause a lot of things were custom on it from our normal build and one of them was the engine and the transmission and then the narrowing of the rear end,” explained Thurmond.


The interior and frame (top) have yet to come together on this glorious white ’63 split-window’s body (bottom), but once it’s finished, it will command well over 500 hp at the rear wheels.

That narrowing was by a total of three inches, allowing for use of wider wheels and tires for the definitive pro-touring purpose so many of Thurmond’s customers seek. The car is one of GTS Custom’s longest-staying guests, having been in progress for close to three years. “This is like one of my standby customers you could say,” joked Thurmond. “Really, all he cares about is that when it’s done, it’s been done to the best of our abilities.”

The motor, meanwhile, was in a third area. An LT5 sourced from an original ZR1, it’s been rated to produce 580 hp, but has “crazy electronics and everything it takes to make it run is quite complex,” according to Thurmond.


This green 1965 body has been in progress for nearly 10 months, and has about that many left in shop time. Here, it is in the midst of the wiring and air conditioning installation phase.

The last of the C2s was a green 1967 specimen, awaiting its Newman chassis and standard LS3 with Tremec T56 transmission. “It’s still a good eight to ten months away from completion,” commented Thurmond. “It’s probably been here about that long already.”

Once finished, the Vette will give off a sleeper impression, looking totally stock–even down to the factory Goodwood Green paint–while packing all that LS-powered heat underneath. For now, however, the car is seen fit to have its wiring, window regulators, and air conditioning installed.


This 1965 model is in rough shape, but Thurmond sees greatness behind its gnarly exterior. A new front clip is in order, as is media blasting and touch-ups to any damaged areas of fiberglass.

In the other room of the shop, a crude and modded C2 sat bare with no front clip. A blown-up LS6 from Scarlet sat roughly where a working engine would go, and was done only as a workaround to red tape issues regarding registration.


The mocked-up motor seen here was a workaround to get the car registered. “It’s a blown-up LS6 from my autocross C2, Scarlet,” said Thurmond. “We threw this in to get it legal as a ‘2014 special construction.'”

“We’ve got the front end ordered, and the rest of it basically is not in too bad of shape,” said Thurmond. “All the paint and everything will be removed and then all the glass repairs will be done. There’s cracks in the door there that’ll have to be fixed.  Just grind it all out and feather it out and put fiberglass in its place.  It’s pretty easy really.”

At a relatively fresh two months in, this was the latest project under the roof at GTS Customs. “Got all the paperwork done. I got the title in the mail the other day so I can actually feel comfortable to start workin’ on it,” said Thurmond.



This ’61 is undergoing serious work in the paint booth. The customer asked for prismatic paint, and so far, it looks like it was a great choice.

After surveilling and milling about for the better part of the day there at GTS Customs, we’d seen, heard, and experienced what made the shop and its founder tick. Alongside his faithful employees, including his son Weston and associate Patrick, the three men manage to produce some of the coolest custom creations this side of the Rockies.

Even after decades of driving, racing, and working on Chevrolet’s halo car, Thurmond has yet to feel the passion extinguish. “Everything from the handling to the styling to the horsepower is part of what has made me a lifelong Corvette fan,” he confesses. “Chevy devoted more time, effort, and money to the platform than any other, and I try to follow that example with the work that I do here.”

We salute Thurmond for his ongoing love affair with the Corvette, and can’t wait to see what else he’ll produce in the years to come. Find his website here, and be sure to stay connected on Corvette Online as we bring you Part Two of the GTS Customs saga: Scarlet, the autocross racing C2 Stingray, which will arrive next month.

About the author

David Chick

David Chick comes to us ready for adventure. With passions that span clean and fast Corvettes all the way to down and dirty off-road vehicles (just ask him about his dream Jurassic Park Explorer), David's eclectic tastes lend well to his multiple automotive writing passions.
Read My Articles

Late Model LS Power in your inbox.

Build your own custom newsletter with the content you love from LSX Magazine, directly to your inbox, absolutely FREE!

Free WordPress Themes

We will safeguard your e-mail and only send content you request.

LSX Magazine - The Late Model GM Magazine for Camaro

We'll send you the most interesting LSX Magazine articles, news, car features, and videos every week.

LSX Magazine - The Late Model GM Magazine for Camaro


We will safeguard your e-mail and only send content you request.

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

Corvette Enthusiasts

Performance Driving

Engine Tech

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

  • Corvette Enthusiasts
  • Performance Driving
  • Engine Tech

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Thank you for your subscription.

LSX Magazine - The Late Model GM Magazine for Camaro

Thank you for your subscription.

Thank you for your subscription.