Thanks, this is the info from BlueOvalTrucks.com:
I like the length, just was suspicious since other makes have a variety.
1992-2014 Econoline 138.0″
This.Iirc...somewhere in the 80s they went to one wheelbase for the non chassis cab ....vans. I know post 95 it is 138....I had quite a few for work trucks ...mostly e 350...that were 138....even the extended vans.