GMT400
The GMT 400 and similar GMT 480 was the platform for the 1988-1998 model year full-size pickup truck. The GMT 410, GMT 420, GMT 425, and GMT 430 were used for full-size SUVs from late 1991 to 2000. This was the first GMT designation for the C and K full-size trucks and SUVs.
The engineering for the GMT400 was done by the GM Truck & Bus group, working primarily out of a rented facility at Pioneer Engineering on 9 mile Road in Warren, MI.
GMT 400 frames were built by A.O. Smith Automotive Products, Dana Holding Corporation, and Tower Automotive.
Engines included the gasoline 4.3L-V6, 5.0L-V8, 5.7L-V8, 7.4L-V8, and diesel 6.2L V8 and 6.5L V8. Throttle body fuel injection was used on '88-'95 gas engines. CPI was used on the '96-'00 4.3L-V6, 5.0L-V8, 5.7L-V8, while the '96-'00 7.4L-V8 used SFI.
The GMT400 series was replaced by the GMT800 vehicles beginning in 1998. The GMT400 models were built at Ft. Wayne, IN, Pontiac, MI, Flint, MI, Oshawa, ON Canada, and Janesville, WI & Arlington, TX.
Applications
| Basic platform | Years | Model | Notes |
| GMT400/480 | 1988–2000 | Chevrolet C/K | |
| GMT400/480 | 1988–2000 | GMC Sierra | |
| GMT410 | 1992–1999 | Chevrolet Suburban | |
| GMT415 | 1992–1994 | Chevrolet Full-Size Blazer | |
| GMT420 | 1995–2000 | Chevrolet Tahoe | |
| GMT425 | 1992–1999 | GMC Suburban | |
| GMT430 | 1992–2000 | GMC Yukon | |
| GMT435 | 1999–2000 | Chevrolet / GMC Chassis Cab Models | |
| GMT455 | 1991-2002 | Chevrolet/GMC C3500 HD |