My 1952 4400 has 161" wheelbase and 7.50-20 tires / rims and a PTO. GVW is 12500 lbs
There are very few differences between the 4400 and the 6400, the front wheel track width on a 4400 is 56" and on the 6400 it is 58-3/4"
Other than that springs and tire size is the only difference. The lightest duty 6400's came with 7.50-20 tires/rims and were rated at 13,000lbs GVW while heavier duty 6400's came with 8.25-20 tires with a GVW of 16,000 lbs.
Curb weight for the heavy version of the 4400 and the light version of the 6400 is only 45 pounds different.
