1969 upper defroster seal

[x66 714]

The parts book calls for a 3949921 seal for the defroster duct where it contact with the slot in the bottom of the dash panel. What are you guys using? Thanks, Joe

[firstgenaddict]

I used this same type of foam, it has a thin plastic backer that has adhesive on it.
The stuff I pulled off the original duct looked similar - clear plastic backing, with what appeared to be remnants of open cell foam.
It compresses well and fills the gap eliminates another rattle point etc...
FWIW I am pretty sure that the gauge lenses or bezels have foam strips at the top, very narrow 1/4" wide x 1/4" high 2" long open cell foam just keeps things from rattling when you are driving or closing the doors.
 I use it on the the vent duct outlets and most, if not all of vent duct joints.

This is my brother's 73 Z but first gens have similar albeit round ducts - I use which ever height foam I need to fill the gap on ducts, but not so much that it is at all difficult to push the duct on the other.


I got it at lowes or home depot.
I imagine the longevity may be double that of the originals... lol 

[x66 714]

Thank you James. That's what I was thinking due to what was left at the top. Off to get some this morning....Joe

[Edgemontvillage]

The duct seal on my car has completely disintegrated so I used the HAC-1030 seal kit from HBC which is a Re-pops product. The distribution duct-to-underdash seals in the kit are made from a denser cell foam material that allows the duct to be seated firmly but won't over-compress so the plastic duct doesn't contact the dash and cause a buzz or rattle. The rest of the kit is horrible, unusable actually, but the duct to underdash seals are good and well formed. I used 3M Weatherstrip Adhesive which sets up in a few minutes and doesn't dissolve the foam seal.

[x66 714]

Thanks Lloyd...Joe

[firstgenaddict]

Remember to install the White wire which crosses from door jamb switch to door jamb switch prior to the distribution duct - you probably can't get it behind the duct after installed.

Here is a photo of N633599 - you can see the wire is behind the duct then through the hook at the center of the dash then behind the pass side duct.



It also goes between the dash top and the brake clutch pedal support
N633599

[x66 714]

Thanks James. I also figured out the oil line goes back there. Lots to remember after 2.5 years. If you take 100 pictures, you will need 200 more....Joe