A black sports car with a silver center stripe is parked in a garage next to a car covered in clear plastic. Another dark blue car is elevated on a blue hydraulic lift, and a man stands underneath it.

CUSTOM PROJECTS AND CONVERSIONS

From powertrain conversions and modernization to complete vehicle overhauls, Sunday Spec takes on larger projects that require careful planning, sourcing, fabrication, and integration.

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OUR FEATURED PROJECTS

  • Oscar's 2015 Volkswagen GTI

    This GTI came to us as a project car the owner wanted to completely overhaul, with the goal of blending show-car looks with something he could still enjoy driving every day. We handled the major pieces of the build, including the air suspension, custom VMR wheels, intake and valved exhaust, aero kit, lighting, and a custom audio system.

    Modifications Include:

    • Bag Riders Super Low air suspension system
    • Custom VMR wheels
    • Integrated Engineering cold air intake
    • Custom valved exhaust system
    • Maxton Designs full aero kit
    • LED headlight conversion
    • Sundown Audio 10" subwoofer, amplifier, and custom enclosure
    • VIOFO dash cam system
  • trans am lsx twin turbo huron speed btr intake

    Sean's 1999 Pontiac Trans Am

    Sean’s Trans Am has been his personal project for more than a decade, built and refined piece by piece over the years. What started as a cammed LS1 street car eventually evolved into a 800+ horsepower twin-turbo street monster.

    Modifications include:

    • LME forged 408ci LS engine
    • MAST Motorsports heads & custom camshaft
    • BTR intake manifold
    • Huron Speed twin-turbo system
    • RPM T56 transmission
    • Monster triple-disc clutch kit
    • Strange Engineering 12-bolt rear end
    • Lowering springs and adjustable rear suspension
    • Line lock kit
    • Coil pack relocation
    • 19" VMR wheels
  • A dark blue Chevrolet Tahoe SUV parked on an asphalt surface with a background of green trees.

    1995 Chevrolet Tahoe 4x4 (IN PROCESS)

    This is the first Sunday Spec in-house project that will become the ultimate 2-door OBS Tahoe daily driver. The build showcases the team's capabilities and balances performance with reliability and quality of life to give the owner years of enjoyment whether on a daily commute or weekend cruise.

    Modifications include:

    • Engine conversion: GM L86 6.2L
    • Stage 1 performance camshaft kit with DOD/AFM delete
    • Custom exhaust system
    • Sunday Spec custom cold air intake
    • Transmission conversion: GM 10L80 transmission w/ 4WD retained
    • 17" Black Rhino wheels and Nitto Terra Grappler tires
    • Little Shop Mfg complete brake package (rear disc conversion, front disc upgrade, and master cylinder)
    • Refreshed steering and front end components
    • Double-din Sony head unit w/ Apple CarPlay and back-up camera
    • Full Kicker audio system
    • Upgraded lighting
    • Weathertech floor mats

  • Les' 1994 Chevrolet Corvette (IN PROCESS)

    This 1994 Corvette is a full custom build centered around making the car feel completely re-engineered without losing what makes a C4 special. The project includes a 427ci LS-based powertrain, extensive engine-bay cleanup and fabrication, upgraded cooling and accessory systems, custom exhaust, and a long list of detail work aimed at creating a high-end show car that is still built to be driven.

    Popular services include:

    • Engine conversion: Texas Speed 427ci aluminum short block
    • PRC CNC ported cylinder heads
    • Custom camshaft and matched valvetrain components
    • Custom stainless headers and full exhaust
    • Holley Terminator X Max control system
    • Drivetrain conversion: Late Model Transmission 6L80E
    • Circle D billet torque converter
    • Ridetech coilovers and adjustable control arms
    • Wilwood big brake kit (front & rear)
    • Double-DIN Apple CarPlay head unit
    • Full LED lighting conversion (interior & exterior)

OUR PROJECT PROCESS

Custom projects are easier when the next step is clear. Here’s how we take the conversation from first idea to finished work and long-term support.

  • Phase 1: Consultation & Vehicle Review

    We start by discussing your vehicle, goals, budget, and how you plan to use the car. For older vehicles, previously modified cars, or larger projects, we may need to review the vehicle in person to understand its current condition before making recommendations.

  • Phase 2: Estimate, Deposit & Parts Planning

    Once the direction and goals are clear, we prepare the estimate, collect the deposit, and begin sourcing the parts needed for the project. This step helps lock in the plan, timeline, and components before the vehicle arrives.

  • Phase 3: Drop-Off, Installation & Setup

    When your scheduled drop-off date comes, your vehicle will arrive to our Alpharetta facility for installation, setup, tuning, fitment, or custom work. We keep you in the loop every step of the way with weekly updates and progress pictures through our communication systems.

  • Phase 4: Delivery, Walkthrough & Support

    During delivery, we walk you through the work performed, answer questions, and help you understand how to care for the vehicle moving forward. After the build, we stay available for follow-up, maintenance, adjustments, and future upgrades.

BUILT WITH CONFIDENCE

Sunday Spec supports every custom project with clear scopes, documented approvals, regular communication, and a 12-month workmanship warranty.

ABOUT SUNDAY SPEC
12-Month Workmanship Warranty

All packages and custom projects are guaranteed by a 12-month warranty on our workmanship.

Communication Throughout the Project

Customers receive clear updates as the project moves through planning, fabrication, installation, and testing.

Post-Delivery Support

We remain available after delivery to answer questions, address concerns, and support the finished vehicle.

READY TO GET STARTED?

Contact our team and see how we can transform your vehicle!

START YOUR PROJECT