hello can any one tell me the difference between the m54 5/ton and the m812 5/ton can i fit the 14/20 wheels from the m812 on the m54 many thanks
Not too handily if you plan on using them as duals.
These trucks began as the M41, which used 14.00-20 tires in a single wheel configuration with the wheels having a different offset than those in dual wheel configuration. The M54 was a dual wheel version of the M41, using 11.00-20 tires. Both the M41 and the M54 were powered by the Continental R6602 gasoline engine.
The M54A1 was essentially the same, but the powerplant was a Mack ENDT-673 Diesel engine.
The M54A2 was again essentially the same, but powered by the LDS-465 Multifuel engine.
Seeking further improvements in this range of truck, the Cummins NHC-250 was installed. The longer length of this engine required the lengthening of the engine bay and hood, and the M809 series was thus born.
The M812 was a specialized chassis variant in the series used for transporting bridges and missiles. The equivalent truck in the older series was the M139. These specialized chassis use the 14.00-20 tires in a dual wheel configuration, which requires special spacers, and results in a truck that is over legal width, requiring permits.
Hope this helps,
David Doyle