One difference that I haven't seen on any of lists posted
is the change in the fuse block.  I think it coincided with
the change to the 2.1 in '86.  Before--simple fuse block
with the old-style ceramic fuses; after--very complicated
fuse block with modern-style fuses and wiring harness plugs
on the back and relays on the top.  (If you don't believe
it is complicated, open one up!)

                        Richard A Jones
                        Boulder, Colorado