1955 Belair convertible
55 convertible - I pulled the deluxe heater to clean and make repairs. It didn't work at all. Now I'm ready to install and am having a devil of a time. I think my problem is that I installed the right piece first and now I can't get the left piece up under the dash. The heater core tubes hit the floor. Just looking to confirm the left piece should be installed first and THEN the right piece?