it depends on what setup you have to the way it needs to be done.
theres several variations of columns and the lower bearing area varies from later column shift to early floor shift models and is a reason for some confusion about the subject.
in your case, the early shaft fits with some trimming, this is a type of setup i had earlier.
but there are variances in the aerostar shaft as well and sometimes you need to combine an early and later aerostar shaft with some trimming to make it work. especially on later 2wd non body lift applications.
i have made many of these over the last 15 years or so specifically for ranger v8 swaps, late 95 or early 96 i went to the aerostar because of issues with the rag joint and v8 heat combined with a 4 in body lift i had for awhile.. some study at the steering shafts available at the junkyards pretty much gives a guy any result he needs.
this is a different setup i run when swapping the 6.5 diesel in...
that was when i had the chevy box on still.
i went to a ford box so i could fit that fat bastard radiator in there so i have a bit of a different setup these days as well.
lets just say i i pretty much have less then 50 bux so into all of my steering shaft setups over the last 16 plus years now on my rig in these pictures, and all were better then the junk that the truck left the assembly line with.
the link posted by wahlstrom1, iirc i think that guy actually consulted me about this, glad he did a write up in any case.
unfortunately there are some variances like mentioned, and i have been questioned repeatedly because of that...i just make shit work the way i want and i forget about small details often....