What did you ask Santa for back in 2019? Hopefully it was something good. Even though Cynthia Pierce of Springtown, Texas, didn’t ask for, or expect to find a 1978 GMC Jimmy parked underneath the Christmas tree, her husband Eric surprised her with one. Talk about a great gift giver! The Pierces didn’t waste much time to not only work on keeping the Jimmy on the road, but to go above and beyond to get it ready to hit the show circuit.
Before we get too ahead of ourselves with this story, however, Cynthia made it a point to explain to us where the truck came from and what their next moves with the GMC would be. “This K5 lived most of its life in the Texas panhandle, but we acquired it in Tennessee from the infamous Boris Maryanovsky at Street Machinery”, she says. “When we got the truck, it had the original small block 400 engine and matching 400 transmission but we didn’t really tear into it until the AC compressor went out. It was then when we decided to bypass that single repair issue and looked toward the bigger picture of what we really wanted from the truck.”
Cynthia currently works for Revzilla – a legitimate candy shop for motorcycle enthusiasts. She has always been into cool two- and four-wheeled modes of transportation thanks to her awesome folks. “I’ve been into this kind of stuff since birth. I came home from the hospital back in 1983 in my mom’s 1969 GTO that my dad still owns and takes out on the Power Tour every year”, she admits. “My parents were always wrenching or racing, and I have so many memories of us cruising and spending time at the local drag strips, street races, and car shows. That kind of automotive lifestyle was instilled in me very early on.”
It’s no wonder why Cynthia’s husband would make the grand gesture of surprising her with a 43-year-old GMC SUV without feeling there would be a backlash of some sort. It’s a beautiful thing to see two loving gearheads enter holy matrimony together, and even better to see what kind of awesome vehicles sprout from that union. “Ultimately, we planned on blowing the Jimmy apart completely and start building it to match a 1977 Chevy C10 dubbed ‘Sorority Girl’ that Pro Touring Texas had built.”
For those who haven’t seen this C10 that Cynthia has referred to or have yet to see the quality of work that Pro Touring Texas has been putting out lately, just know that setting a goal to match its stature is a lofty wish for sure. Luckily, the Pierces were able to get Pro Touring Texas on board with their Jimmy project named Sorority Sister. From that point on, there was no pondering ‘if’ the transformation would ever take shape, but rather a matter of ‘when’.
Once the GMC was at the Pro Touring Texas headquarters, it was given a similar suspension treatment as its C10 Sorority Girl counterpart. The pickup they built was lowered modestly to deliver the purpose of performance, not ‘bagged simply for show. To get the Jimmy sitting at a much more respectable height, Ridetech tubular arms with coilovers and Fox HQ Series shocks were added to the front end for a cushy yet responsive ride quality. The lower arms did have to be modified somewhat in order to create more turning radius for the upcoming wheel selection, but it wasn’t anything that the crew at Pro Touring Texas couldn’t handle.
In fact, they had to modify the rear Ridetech parallel four-link system fit as well. “One of the toughest portions of the build was having to re-engineer the Ridetech parts that were designed to work on a C10 to fit correctly on the Jimmy”, says Cynthia. Once the suspension components were successfully customized and installed, upgraded Baer Pro+ 6-piston 14-inch brake kits with the American flag etched in to pay homage to this beautiful country we live in.
A staggered set of 19×10 and 19×12 Billet Specialties Razor wheels was then bolted into position. Now, it if wasn’t for the modification of the front lower arms and the five inches of shortening of the Chevy 12-bolt rear end, there would be no way to squeeze in wheels of these widths, but that’s just the type of thing the guys at Pro Touring Texas do day in and day out. To significantly increase the Jimmy’s traction, 285/35 and 345/20 Nitto Invo tires where slung over the big billet hoops for true street performance with excellent ride comfort.
Next, the Jimmy’s original small block and trans were replaced with a GM Performance LS3 power plant and a matching 6L90E 6-speed automatic. The new engine was soon outfitted with a Texas Speed camshaft, a Holley mid-mount accessory drive and valve covers, as well as a custom 4-inch aluminum air intake, 1-7/8-inch Ultimate Headers tubes, and Magnaflow mufflers to promote a heavy dose of cool, fresh air. Even though this setup is substantially better than the truck’s old factory powertrain, Cynthia admits that if she could do it over again she would most likely go in the direction of a brand new LT backed by a 10-speed transmission. Maybe we’ll get to see a new version of this truck before too long, but for the moment, she’ll have to make do with the 550hp and 493-lbs-ft of torque that her LS mill is delivering. Hey, it could be worse.
When Cynthia mentioned that she wanted her Jimmy to be a spitting image of Pro Touring Texas’ ’77 Chevy Scottsdale, she wasn’t kidding. It sports the same exact original exterior colors and interior styling as well – right down to the SMS plaid fabric sewn up by PG Auto Upholstery and matching plaid graphics printed on the Josh Hart wheel tubs. Keen eyes will even notice that both trucks run the same Billet Specialties wheels in the same sizes, and have the same Pro Touring Texas edition Dakota Digital gauges wired into the dash. While these two classic GM trucks aren’t exact twins, they are kindred spirits, indeed.
Once Pro Touring Texas set the Jimmy free into Cynthia’s care, she and Eric hit the road from Ft. Worth to show it off during last year’s installment of Dino’s Git Down. “Alongside the Pro Touring crew driving in their ’75 GMC Sierra Classic Beau James edition pickup, we were finally able to get well acquainted with our newly updated Jimmy”, Cynthia says. “On the way out to Phoenix, we stopped at a buddy’s place for a get-together in Amarillo. Turns out a gentleman there for the same reason remembered our Jimmy when it was brand new in Amarillo, and he confirmed that it was originally white and blue like we suspected, and that the top had never been taken off. The stories we traded and the memories he had of the Jimmy will forever be in my heart and part of the story.”
CYNTHIA PIERCE • ‘78 JIMMY
- GM Performance LS3 376
- Texas Speed VVT 1.2 camshaft
- GM Performance aluminum cylinder heads
- Dual 660 platinum valves
- Stock rockers w/ Smith Bros trunnion kit
- Holley mid-mount accessory drive, valve covers, and engine dress-up parts
- Spal fans
- Champion aluminum radiator
- LS3 intake manifold, 4-inch custom aluminum air tube
- PSI wiring harness
- Ultimate Headers 1 7/8-inch-long tube headers w/ 3-inch collector
- Custom stainless 3-inch exhaust system by Pro Touring Texas, Justin, TX
- Magnaflow muffler
- GM Performance 6L90E transmission
- Circle D 3200 billet plate torque converter
- Custom 4-inch driveshaft w/ Sonnax billet flange
- Ridetech front tubular arms w/ coil-overs and cross bracing
- Modified lowers for more turning radius of 19x10 wheels
- CPP modular spindles
- Ididit steering column
- HyperCo springs
- Fox HQ Series shocks
- Baer Pro+ 6-piston 14-inch brakes (American Badass Edition)
- Detroit Speed master cylinder and booster
- Factory modified K5 pedal assembly
- Factory 30-gallon fuel tank w/ Aeromotive retrofit 340LPH pump
- Chevy 12-bolt 3.42 rear end
- 1510 Moser alloy axles shortened 5 inches
- Cross-braced parallel 4-link w/ modified Ridetech coil-overs and panhard bar
- 19x10 and 19x12 Billet Specialties Razor wheels
- 285/35ZR19 and 345/30ZR19 Nitto Invo tires
- Original Hawaiian blue/white paint
- Graphics by Pro Touring Texas / Graphic Disorder Sorority Sister graphic
- GM headlights, outer mirrors, front and rear bumpers, door handles, glass and chrome
- Rear seat shortened 4 inches on each side to fit rear AMD wide wheel tubs
- Floor mods made to fit 4-link
- Bead rolled and smoothed firewall by Josh Freeman @ Freeman Fabrication, Denton, TX
- Inner fenders hand made by Josh Hart
- Stock bucket and bench seats covered in SMS plaid fabric and leather by PG Auto Upholstery, Haltom City, TX
- Custom fabricated raised center console
- Dakota Digital gauges
- Kenwood head unit, signal processor and amps
- Hertz 6.5-inch front and rear speakers and two 10-inch subwoofers
- Vintage Air A/C
- Sanden compressor
- Dynamat insulation
- American Autowire installed by Pro Touring Texas