1984 GMC K3500 Engine: 4.8L L6; Blower Selector Switch | Rotary;. 1984 GMC K3500 Engine: 5.7L V8; Blower Selector Switch | Rotary;. 1984 GMC K3500 Engine: 6.2L V8; Blower Selector Switch | Rotary;. 1984 GMC K3500 Engine: 7.4L V8; Blower Selector Switch | Rotary;.
