I have a 66 and am replacing the heater core and while I am at it rebuilding the heater box as well. That thing was a mess!
When I got the car the hose clamps on the heater core were attached on the engine side of the firewall.
Reading the FORD drawings indicates the clamps on the inside of the firewall.
Which is best? I am not concerned about being correct, just leak free!
sparx

When I got the car the hose clamps on the heater core were attached on the engine side of the firewall.
Reading the FORD drawings indicates the clamps on the inside of the firewall.
Which is best? I am not concerned about being correct, just leak free!
sparx