One is a six wheeler, one is a ten wheeler as I recall
630 is the general series number. The last digit replacing the zero is an indicator of the wheelbase length. 631 = 141", 632 = 153", 633 = 165", 634 = 183", 635 = 201". If the truck was a factory 3-axle, the letter "W" would be included in the model number, which means dual drive rear axles. The lack of a "W" indicates a single rear axle. Example ("D" = diesel engine, by the way): D632 or DW632.
("Six wheeler" and "ten wheeler" are both 3-axle trucks (tandem rears) as opposed to 2-axle trucks (single rear). All 3-axle trucks have ten wheels (dual rears). "six" and "ten" are just two ways of counting/naming the wheels on the same 3-axle truck.)
1957 GMC 632 tractor
in Other Truck Makes
Posted
630 is the general series number. The last digit replacing the zero is an indicator of the wheelbase length. 631 = 141", 632 = 153", 633 = 165", 634 = 183", 635 = 201". If the truck was a factory 3-axle, the letter "W" would be included in the model number, which means dual drive rear axles. The lack of a "W" indicates a single rear axle. Example ("D" = diesel engine, by the way): D632 or DW632.
("Six wheeler" and "ten wheeler" are both 3-axle trucks (tandem rears) as opposed to 2-axle trucks (single rear). All 3-axle trucks have ten wheels (dual rears). "six" and "ten" are just two ways of counting/naming the wheels on the same 3-axle truck.)