621K Wheel Tractor-Scraper
- Flywheel Power: Tractor/Scraper
- 304 kW (407 hp)
- Scraper Capacity: Heaped
- 24 yd3
- Top Speed (Loaded)
- 34 mph
631K Wheel Tractor-Scraper
- Scraper Capacity: Heaped
- 34 yd3
- Top Speed (Loaded)
- 35 mph
- Width – Overall Machine
- 155 in
637K Wheel Tractor – Coal Bowl Scraper
- Top Speed (Loaded)
- 35 mph
- Flywheel Power - Tractor/Scraper
- 425 kW (570 hp)/216 kW (290 hp)
- Scraper Capacity - Heaped
- 50 yd³
637K Wheel Tractor-Scraper
- Scraper Capacity: Heaped
- 34 yd3
- Top Speed (Loaded)
- 35 mph
- Width – Overall Machine
- 155 in
651 Wheel Tractor-Scraper
- Tractor Engine
- Cat C18
- Flywheel Power - Tractor/Scraper
- 469kW (629 hp)
- Net Power
- 469 kW/637 hp
657 Wheel Tractor-Scraper
- Tractor Engine
- Cat C18
- Scraper Engine
- Cat C15
- Flywheel Power - Tractor/Scraper
- 469kW (629 hp) / 353 kW (473 hp)
657G Wheel Tractor-Scraper
- Top Speed (Loaded)
- 33 mph
- Wheelbase
- 36 ft
- Flywheel Power - Tractor/Scraper
- 447 kw (600 hp) / 337 kW (451 hp)