Part Type: HVAC Pressure Switch. Compatible Years: 1973 1974. 1973 GMC G35/G3500 Van Engine: 4.1L L6; with System Mount Switch;. 1973 GMC G35/G3500 Van Engine: 5.7L V8; with System Mount Switch;. 1973 GMC G35/G3500 Van Engine: 5L V8; with System Mount Switch;.
