1&2 I think are for the Freshair heater hoses.
3. Is where the heater motor mounts through the firewall.
4. Is I think where a Ranco water heater valve .
Hopefully an expert will be by to confirm.
I don't have any of them on my truck.
See attached picture for reference. Not Mine.
Todd
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Last edited by Shaffer's1950; 02/29/2024 5:44 AM.
1950 Chevy 3100