According to the 1950 Vehicle Information Kit
3100 front track of a 3100 is 56-9/16" and rear track is 61"
6400 front track is 58-3/4" and rear inner track is 57-3/4" and rear outer is 79-1/4" with average rear track of 68-1/2"
So while the front track is slightly narrower, the rear track is wider on the big bolts.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.