-26%
Click to zoom in
Large-Face Mushroom Button Twin Plate for Custom Racing Switch Panels
The Granatelli GMS789464T is a mushroom twin switch plate that accepts two large-face mushroom .635-inch barrel-style switch buttons arranged side by side. The mushroom button profile provides a wider, more tactile actuation surface compared to standard face buttons, making it easier to locate and operate switches by feel while wearing gloves or under the physical demands of track driving. Compatible with the Granatelli 10-inch D-shaped racing steering wheel switch panel and any housing that accepts .635-inch barrel switches. Switches and the steering wheel are sold separately.
Key Features
- Mushroom Button Format: Large-face mushroom profile provides a wider, more tactile actuation surface for gloved or high-stress driving environments
- Dual Side-by-Side Layout: Accepts two .635-inch barrel mushroom switches arranged side by side for independent actuation
- Universal Fit: Compatible with any switch housing or panel that accepts .635-inch barrel-style switches
- Race-Ready Construction: Built to Granatelli's competition-use standards for reliable actuation in demanding environments
Specifications
| Detail | Value |
|---|---|
| Part Number | GMS789464T |
| Brand | Granatelli Motor Sports |
| Switch Button Diameter | .635 in (barrel-style) |
| Button Count | 2 (side by side) |
| Button Style | Large-face mushroom |
| Fit | Universal |
| UPC | N/A |
What's Included
- 1x switch plate
About Granatelli Motor Sports
Granatelli Motor Sports is a California-based performance parts manufacturer with roots in professional motorsport. The company produces ignition systems, interior accessories, and racing components used across drag racing, road racing, and high-performance street builds.
Related Parts on Our Site
Frequently Asked Questions
What is the GMS789464T?This is a Granatelli Motor Sports mushroom twin switch plate that accepts two large-face mushroom .635-inch barrel-style push buttons side by side. It is a universal accessory for drivers who prefer a larger, more tactile button surface for switch actuation while wearing gloves or driving at track pace.
What is the difference between mushroom and standard face buttons?Mushroom buttons have a wider, raised dome-shaped cap that extends above the panel surface, providing a larger actuation area and a more positive tactile feel. Standard face buttons sit flat to the panel. Mushroom buttons are generally preferred in racing applications where switches must be located and activated by feel alone.
What is the difference between the Granatelli switch plate options?This plate uses two large-face mushroom buttons side by side. The standard twin (GMS789465T) uses two flat face buttons side by side. The double (GMS789464D) positions one button per side for wider spacing. The single (GMS789464S) accepts one button with 4-position orientation. Choose based on button style and switch count needed.
Is this compatible with the Granatelli 10-inch D-shaped steering wheel?Yes. This plate is designed to be compatible with Granatelli's 10-inch D-shaped racing steering wheel switch panel and any housing that accepts .635-inch barrel-format switches. The steering wheel and switch buttons are sold separately.
What switch buttons are compatible with this plate?This plate accepts .635-inch diameter barrel-style push buttons. Verify your intended switches match this diameter and barrel mounting style before ordering. Switches are sold separately and are not included.
Are switch buttons included?No. This is the mounting plate only. You will need to source compatible .635-inch barrel-style switch buttons to complete the installation.
Can this be used in a street car?Yes. This is a universal accessory and can be installed in any vehicle with a compatible switch panel housing, not exclusive to competition use.
How do I wire the switches after installation?Wire each switch button to the intended circuit per the switch manufacturer's wiring diagram. Ensure each circuit is properly fused. For safety-critical applications such as kill switches or fire suppression, consult a professional installer familiar with competition vehicle wiring standards.
What material is the plate made from?Refer to Granatelli's product documentation for specific material information. The plate is built to Granatelli's race-use standards for durability in demanding competition and street environments.
Installation Instructions
- Verify that your switch housing accepts .635-inch barrel switch buttons and that the plate dimensions match the panel cutout.
- Insert the plate into the panel housing, aligning the button holes with the housing cutouts.
- Seat the .635-inch barrel switch buttons through the plate holes and secure per the switch manufacturer's retention method (clip, nut, or snap-fit).
- Wire each switch button to the intended circuit per the switch manufacturer's wiring diagram; ensure proper fusing on each circuit.
- Confirm all switches actuate freely before securing the panel in the vehicle.
Granatelli Motor Sports
Granatelli Motor Sports carries the legacy of the legendary Granatelli racing family into the performance aftermarket, producing ignition systems, performance filters, and engine upgrades that carry the heritage of a family that won the Indianapolis 500 and competed at the highest levels of American motorsport for decades. The brand is particularly known for its high-performance spiral-wound ignition wires that dramatically reduce radio frequency interference and improve spark delivery in high-compression and modified engine applications. Granatelli products cover a wide range of domestic V8 platforms including GM LS and small-block, Ford Modular, and Chrysler Hemi engines, as well as import performance applications where quality ignition components make a measurable difference in power delivery and consistency. The combination of racing heritage and practical performance engineering makes Granatelli Motor Sports a respected name among serious enthusiasts. Popular Upgrades Granatell...
View Granatelli Motor Sports Products
Interior Parts & Accessories
Enhance your driving experience with our extensive collection of Interior Parts & Accessories. Auto interior repair goes beyond aesthetics; it plays a crucial role in ensuring safety and comfort. Explore our variety of products designed to protect, organize, and personalize your vehicle's interior. Why Choose Our Interior Parts & Accessories? Durable Protection: Floor mats shield your car from dirt and mud, keeping it clean. Essential Safety Components: Gear shift knobs, ignition lock cylinders, and rearview mirrors are vital for safe driving. Affordable Upgrades: Car seat covers add comfort and style while protecting your upholstery. Featured Products Upgrade your car's interior effortlessly with our Car Seat Covers. They provide: Comfort and cushioning Stylish colors and patterns Pet-friendly options like bench seat covers Steering Wheel Covers & Floor Mats Customize your vehicle further with our Steering Wheel Covers and Floor Mats: Protect original upholste...
View Interior Parts & Accessories Products
Steering Wheels
Aftermarket steering wheels improve driver feel, reduce weight, and add a more aggressive cockpit aesthetic compared to factory equipment. Sport and racing steering wheels are available in a range of diameters, grip materials, and hub adapter configurations to fit most vehicles. Popular Steering Wheel Options Popular steering wheel choices include compact sport steering wheels with suede or leather grips, flat-bottom steering wheels for improved thigh clearance in lowered vehicles, full racing steering wheels with quick-release hubs, and wood-rimmed or retro-style steering wheels for classic builds. Most aftermarket steering wheels require a separate hub adapter kit specific to your vehicle's steering column. What size steering wheel is best for street use? For street use, a steering wheel diameter of 13.5 to 14.5 inches provides a comfortable balance of steering effort and cockpit feel. Smaller diameters, commonly used in racing, increase steering effort and are better suited for t...
View Steering Wheels Products
Steering Wheels & Hubs
Steering wheels and hub adapter kits allow drivers to install aftermarket sport or racing steering wheels on factory steering columns without modification. Hub adapters are vehicle-specific components that match the factory column spline to the industry-standard 6-bolt aftermarket steering wheel mounting pattern. Popular Steering Wheel and Hub Combinations Popular combinations include compact sport steering wheels paired with vehicle-specific hub adapters, flat-bottom steering wheels with quick-release boss kits for track vehicles, and full racing wheel and hub adapter packages. Many hub adapters are available with integrated quick-release mechanisms that allow the steering wheel to be removed for security or to allow easier entry and exit in tight cockpits. How do I choose the right hub adapter? Hub adapters are vehicle-specific and must be matched to the year, make, and model of your vehicle's steering column. The adapter bridges the factory column spline pattern to the 6-bolt mou...
View Steering Wheels & Hubs Products