what's the difference between the fenders of a 87-91 pickup and a 92-96
pickup?

Reason I ask is I finally found a catalog online with a listing for
power antennas

http://www.metraonline.com/catalogs/Metra_catalog_2007.pdf

they say that for a 92-96 I should use a 44-PWFD270 which is apparently
no longer made, but the earlier trucks use a 44-PW22 which looks to be a
pretty universal power antenna.

I did poke around the truck today and discovered that there is a good
amount of room to mount the power unit; if you remove the pass. side
kick panel there is an access plate behind there, if you open that up
you are in the space that is the air intake for the HVAC system and it
appears that there's more than enough room in there to mount a power
antenna motor.

I have no idea what's special about the "right" antenna but I did write
to Metra to ask but have not recieved a response yet.  I suspect that it
might have to do with the base and trim at the fender, in which case I
still have all of the factory antenna save for the mast itself, I ought
to be able to make something work if all my ASSumptions are correct...

nate