Re: 327 Questions

Posted by HH56 On 2020/8/7 12:50:37

7# was stock until 53 when they made a 12# available for some engines and that was retrofittable to some earlier models. Both 7 and 13 were available for 54 and the 13 could also be installed on earlier "if conditions warranted". If you are seeing fog on the windshield that is most likely a leaking heater core with the vapor coming up thru the defroster openings and will probably only get worse.

To remove the core you will most likely need to remove the entire heater box unless by some miracle someone has been in there before and left out two small sheet metal screws on the back of the box next to the firewall. With those screws in place it is impossible to remove the upper half of the box to expose the core without a complete removal of the assy.

On 51-4 models the heater assy is held by studs and nuts accessible only from inside the car and possibly a sheetmetal screw on the engine side. The service manual accessories section has a few pages on fresh air heater installation and shows where the nuts are located. After disconnecting the hoses and Bowden cable operating the air flapper in the air vent assy just reverse the install procedure to remove the unit.

Once you have the core out a radiator shop should be able to repair or replace it. As far as I know there are no NOS cores available so best you could expect would be a used core in whatever condition that might be in. If the car has an underseat heater the core in that could also be in poor condition. The rubber seal on the thermostatic valve stem is also a known source of leaks but usually when that item is the culprit the passenger side carpet pad is damp or if the leak is bad there is unexplained liquid found on the ground under the front door area on the passenger side.