Not that cold out and could use some more heat

[Leah Mueller <muellerl@cadvision.com>]

When coming back home tonight at highway speeds,with outside temperature a
little below freezing, the temp guage on my 86 4kq was at or just barely
over the 70 degree mark. The heater was full on and the air was not quite
comfortable enough.  Back in town the temp registered closer to 85 degrees
at the city speed limit. Any thoughts / experience beyond thermostat?  Does
the 4kq use the same thermostat as a 86 5ktq, since I have an extra one of
those in my garage. Thanks for your help.

David