They're sold separately, for 84/85 cars, since the coil is sold for 86/87 cars. RockAuto shows the following....
...under Ignition Coil Mounting Bracket:
Airtex/Wells 4C1003 -- $6.59 (pic shows both gaskets too)
AC Delco D4002 -- $7.97
....and on Closeout under Ignition Coil Housing:
Kemparts 344F -- $1.25