Hot
Make sure there are no open holes in the firewall. In a recent thread, someone mentioned placing a light in the engine compartment, and looking under the dash from the cabin side in a darkened garage to find any holes in the firewall.
Is the insulation in place on the underside of the tranny tunnel, in addition to the foam collar that rcread mentioned?
Is the normal "hairy Camel" insulation in place on the firewall and on top of the tunnel?
Is the lower dust boot at the tranny shifter intact?
Heater control cables connected and operating correctly.
Leaves out in the cowl area and ducts for the air vents at the kick-panels and dash panels?
Kick-panel control doors sent correctly for maximum opening?
Some guys have an isolation valve in the line between the engine and the heater core, so there is essentially no hot water in the core. I leave in Florida with the black convertible you see in my avatar with a big block and don't need to do this. No A/C, of course. Side-pipes help a lot, but can cause localized overheating on your legs occasionally.













