Deve, If you've got the factory assembly manual, it has frame dimensions on Sec 2, Sheet 2.00.

Front running board mounting holes on the frame bracket are 15.25 inches aft of the front of the dash, which is 13.188 inches in front of the front body mount holes. So the front bracket goes 2.062 behind the front body mount holes.

Hope that helps.

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.