Build Time: Up to 6 Weeks

The DD-EFI 12.3″ Digital Dash is the first fully Plug-N-Play digital display solution for MegaSquirt-equipped vehicles. Designed specifically for 1984–1987 Buick Grand National models, this unit replaces the factory instrument cluster with a high-resolution 12.3″ LCD and custom bezel that fits perfectly into the stock dashboard opening. It delivers modern display technology while preserving OEM aesthetics.

This all-in-one enclosure includes everything needed for seamless integration with your ECU, featuring in-dash tuning, customizable layouts, and full CANBus and I/O support.

Internal I/O Module

7 Digital Inputs
5 Analog Inputs
1 Fuel Level Input
2 PWM Outputs
Ideal for turn signals, high beam, oil pressure, fuel level, and more

CANBus Communication

Interfaces directly with your MegaSquirt ECU
Adds 5 sensor inputs, 7 digital inputs, 2 speed inputs, and 2 PWM outputs via CAN

Built-In GPS

Supplies speed signal for digital speedometer
Enables additional features: latitude/longitude, fuel economy, trip meter, odometer

Software & Features

Full version of TunerStudio pre-installed
Also includes MegaLogViewer and AnyDesk
Custom splash screen
Customizable digital dashboards
32GB internal storage for automatic data logging
Sleep mode after ignition off
Auto shutdown (default 60 min, user-configurable)

Custom Grand National Bezel

Direct bolt-in replacement for 1984–1987 Buick Grand National factory cluster
Matches factory dashboard for OEM+ appearance

What's Included

DD-EFI 12.3″ Digital Dash
High-resolution LCD screen
Internal GPS
32GB internal storage
Internal I/O Module with full sensor and output support
Power Connector
CANBus H/L wiring to MS ECU
Pre-installed software: TunerStudio, MegaLogViewer, AnyDesk

Buick

12.3″ Standard Dash 84-87 Buick Grand National

Dash Overlay Stickers - Grand National

Dash PNP Install Harness – 84-87 Grand National

12.3″ Pro Dash 84-87 Buick Grand National