John, I still had the original rubber grommet with two holes. Mine had just had the two holes plugged with rubber that popped right out.
My copper pipe was a little thicker than the original brass, but not so thick that the grommet didn't fit.
Could be a little fiddly if you don't already have the grommet- not sure if they are anything standard that can be bought or not- but I am sure there are a fair few old ones hanging around on rusted out old 40's.
The rest of my sealing/gasketing was done with various adhesive rubber foams-
this thread was a lot of help with restoring the heater- except the foam I used was a lot heavier density that what was used in that thread (plus my heater was a different model)- one of them was a PVC rubber I think, and the other some other sort of fancy (expensive) named rubber- both of them rated for reasonable heat resistance and good wear/compression.
For the heater and the blower doors I used adhesive black sheets about 3mm thick, with two layers wrapped around the heater core (only just squeezed in, so is nice and air tight) and the connections between the outer body panel/grill and the blower, the blower and the firewall, both sides of the square ducting and where the square ducting connects to the heater core box- was all done in a strip-roll of really good quality compressible rubber foam about 10mm thick. Even with this there was an odd gap between the blower intake and the grill on the body that I had to caulk- I used black butyl rubber (harden's up on outside and stays soft in the middle). It all looks and works pretty good. The three positions for the heater work properly (fresh, heat/defrost and heat/vent) and with all the foam on the heater doors and stuff there are no rattles/noises (yet).
btw, my last (and still current until it sells) car... van... but it was called a 'truck' too
... didn't have heating- blower had been removed to fit a larger engine- so this is going to be a treat for me
no wiping foggy window anymore- Defrost and warm feet
can't wait
