Originally Posted by liberalswine
Perfect! That's everything I needed. thanks man! Also you are spot on with that last comment. This is exactly what I suspect since I do smell raw exhaust odors coming from under my hood. Again, thanks so much for the useful info!
Although somewhat expensive at $70 for the pair, I purchased a set of block-off plates from Cosworth USA: http://www.cosworthusa.com/store/pc/...&idproduct=365
I also purchased the two OEM gaskets from Chaplin's Subaru (Subaru Genuine Parts).
The Cosworth b-o plates are nice billet aluminum pieces annodized grey/silver with their name stamped on them. They come supplied with allen-head bolts, which I recommend putting a little anti-seize on before installing.
The exhaust feed-back through the valve/air-pump system would last for a few minutes until enough heat was generated to melt or boil-off the water temporarily and then close shut.