Check the vacuum lines on the passenger side out the fire wall. The heater and ac ventilation system runs off vacuum lines. The external air can get stuck open without enough vacuum. vacuum pressure closes it.
new engine,1.7 rocker arms,Pipes exhaust, shorty cats , shorty headers,under drive and overdrive pulleys,4.2 upper plenum, throttle body spacer, cold air intake, stage one clutch, shorty shifter, and tune. 8.8 in storage