This 1987 GMC Sierra Classic R2500 features a replacement Generation V 454ci V8 crate engine installed in 2001, paired with a modified TH400 three-speed automatic transmission with a TCI torque converter and shift kit. Engine enhancements include an Edelbrock intake, Crane CompuCam, Crane Gold roller rockers, MSD ignition, and Headman Hedders with dual stainless DynoMax mufflers. The five-digit odometer has rolled over and currently shows 2,459 miles, with the seller adding approximately 53k miles since acquiring the truck in 1992; corrosion is noted on the hood, bed, rear fenders, and door bottoms, and the passenger side power-lock is inoperable.