[s-cars] UrS4 Heater Core replacement

[Airbil]

Fwiw
I used this waterproof weatherstripping from homedepot.
 http://www.homedepot.com/buy/tools-hardware-hardware-fasteners-weather-stripping/thermwell-products-1-1-4-in-x-10-ft-high-density-rubber-foam-weather-stripping-tape-149083.html
Adhesive side stuck on the hvac box.
I added a small bead of butyl tape from autozone on the firewall opening.   
Set hvac box back in place and tighten it down.
Voila'!
No leaks.
I also have now added some old window screen material at each end of the plenum as crap catchers so the drain no longer cloggs with crap.
Also.... I think the oem heater core may have some sort of manufacturing residue left that takes awhile to burn off so it may be good to wash it with som Dawn or high powered detergent as oppose to beathing it as it evaporates.  Ymmv
Finally dont forget a new fan and oil it up prior to install.
Bill~haten the heater core~m  

                             ~ via airmobil 2 ~