Heater core and resealing inside heater assy

[69Z28-RS]

The heater core in my car was tested *good* by the radiator shop, and I've cleaned up the heater/def box for re-installation and I've a few questions for those of you who have done this before.
1) there was a 'thick material'? on the heater door (behind the heater core) which either served to insulate? or to dampen noise ?from the blower.  Of course this material was deteriorated and came off during the cleaning operation.  Now for re-installation, I'm unsure if I need anything to replace it, and if so, what is the preferred material for doing so ?
2)  The heater core was installed inside the box using a 'weatherstrip' like material to seal the core against the heater box.  Again, this material came off/out when I cleaned it, and again I've a question of what I should use to reseal that area?

The external (firewall) blower motor housing seemed to be sealed to the firewall using gray 3M rope seal, so I plan to put that back to augment what was left there.

PS. I also found a date code on the Heater Core (Harrison 69 J' )     Does anyone know what month J is for heater cores?   is it September?   My car is an 09C..

Any other suggestions from you guys before I do this task?

[Mike S]

 I'd sure like to know too what the materials are in item #1 & #2. Mine has completely fallen off.
As for the letter and numbers that looks to be the date and I believe the letter I was not used in this instance so J looks correct for Sept.
Your date has low lag time between being made vs. installed in your car.
My 5B NOR BB has a Harrison dated M66 (Dec 66) core. I guess BB's didn't take off in sufficient numbers to use the cores more frequently in 67 compared to the smaller block counterparts that used the standard heater core.

Mike

[1968RSZ28]

PS. I also found a date code on the Heater Core (Harrison 69 J' )     Does anyone know what month J is for heater cores?   is it September?   My car is an 09C..

The "J" is stamped, so September would be correct...

http://www.camaros.org/numbers.shtml#GM-InternalDateCodes

Paul

[69Z28-RS]

I'd sure like to know too what the materials are in item #1 & #2. Mine has completely fallen off.

Unless I get some better information from someone here, I'm going to Lowes...
1)  the damping material on the heater flapper door *appeared* very much like the material used inside HVAC return air ducts (to dampen the sound).
2)  The 'seal' between the heater core and the heater/def box *appeared* very much like standard home door weatherstripping (that you use between external doors/windows and their frames. 
And I suspect both these materials would work OK if I can find them at a home repair store.

[BillOhio]

I got a kit from hbc and it came with all the seals. My new core came from there and was alot heavier than the junk one i got from Ricks. I even was damaged

[68Zproject]

http://www.heartbeatcitycamaro.com/store/product/15067/Heater-box-seal-kit-SB-BB/

[Mike S]

 Thanks for that link. I see the kit also has the dash defroster vent duct seals too.
Mine are dried out and certainly need to get replaced.

Mike