Here is a new mount part # 17092 to fit the Meyer EZ classic mount to a 1987-1991 Ford F250, F350. With this kit you get the Meyer clevis 11310 side arms 11234 and 11235 the side arms 11394 and 11395. and Bolt bag 08606 and light elevation kit 08626. This does not come with the tubular lift frame you will need to get that if you don't have it the lift frame only fits the full size trucks lift frame part # 11255.

If you need some measurements from Center to center of the tube it is 23.5"

and center to center on the A frame ears are 23.5".

Here is the parts list and Installation Instructions for 17092