Hi ahhsit..... Thanks for the information and reply.....I decided to write a ton of emails too, to online Subaru dealers who do a lot of business on Ebay and Amazon.... some of them gave vague answers, but a couple did come through with the answer I needed to hear... ironically, I see you are in Boulder CO.... and the unit I ordered is coming from Heuberger Motors I think in Colorado Springs..... It turns out that there are two numbers for this kind of block heater and the one that ends in 000 is the original number..... and that was replaced or what they call "superseded" by the identical number ending in 100...... From what I could see... the 000 unit has the element sticking out further, and the 100 unit is more recessed.... both look identical after that and I have been assured that both will work... So from then on, the only consideration was price.... and I got one ordered for $38 and free shipping which I can live with.... Now I need to find someone with the correct hex head to remove the original plug and also look to see if I have some high temperature silicone for the threads.... Otherwise, someone is another forum said if you are "quick" you can take out the old one and install the new prepped heater plug in one motion which does not require draining the antifreeze... which was installed less than a year ago.... so I will try that with a large pan as a back up in case I turn into a clutz which has been known to happen.... thanks again... Dennis
