Having been underneath my dash trying to figure out how to install a radio, I noticed that my heater box wasn't properly secured and there as about a 1/2" gap between the cowl and the box. The seal in that area was also severely deteriorated along with the foam on the doors.

I did a search through the old postings and Detroit Muscle Technologies has a heater restoration kit for 1966-1976 cars but mine is a 1965 Barracuda. The parts look like they're pretty close but I don't want the car down for a few days waiting for the parts to arrive.

Any advice for what foam I can use temporarily (permanently?) for the vent doors? I was thinking that I would an open-cell foam tape around the perimeter and cut something thicker inside.

If I use an open cell foam tape for the sealing edge of the heat-control door, is it necessary to insulate the back side?

As for sealing the box halves and heater core perimeter, I thought I would use DAP Draft Attack Removable Caulk.

I've appied strips of 3M 1/4" 3" wide open cell foam gasket to the doors with no ill affects (so far so good after 12 years in the hpak duster, this is the wide gasket used for mounting canopies to trucks). Been trying to find some 6"x6" sheets of the same but have come up with zip.
I covered both sides since they had that phiso pad stuff applied to it at the factory.

-D.Idiot

'65 heater assembly is same as '66, so the DMT kit, if it is in fact correct for '66, will work fine for your '65. I've used 1" square foam, cut to length and the the ends glued together, to make new seals between the top of the heater box and the bottom of the cowl.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the replies. I would not have thought to try canopy gasket foam. I'll try a truck cap shop for some.

Any suggestions as to where I could find 1" square foam?

Your friendly home improvement store... In the weatherstripping/door seal, threshold isle...

_________________
MRO....

Cheap, Fast, Reliable.... Pick 2...

The local truck cap shop only carries 1-1/2" and 2" wide foam tape. 2" is the widest he can get from his supplier. He gave me 2' of the 1-1/2" tape as I should be able to double it up and it should be much more effective than the foam dust that is there right now.

It looked like there is also a strip of 5/8" wide by 5/16" thick open-cell foam sealing the hinge side of the temperature control door. I didn't have any luck finding this at Lowes, Home Depot, or Canadian Tire last night but I'll try again today. Closed-cell foam seems to be easier to find than open-cell. The old foam is still in reasonably good shape but I was also going to use the new foam tape to seal my vent doors.

I thought 1" square foam is a bit big but it turns out that there is a 1-1/4" square foam for sealing around window air conditioners. I also found a round foam filler rod that is available in diameters up to 2". I ended buying 1/2" square closed-cell foam tape instead as it seemed to be reasonably close to the old seal's thickness.

The metal plate on the back of the heater box has loose rivets (only 2 were tight), which is probably why it sagged.. I'm going to drill them all out and replace them with bolts. Some of the rivets were loose enough to break the heater housing so I've also got some epoxy repairs to make too.