It will work but the other 73 gigs will be completely useless. Its just like putting it in a Tivo or a computer running old versions of windows that are unpatched. It won't recognize the extra stuff as useable. I suggest you save your money and buy a 120 gig.
I put a 160GB HD in afriends XBOX.It only read 137GB.But thats 17GB more than a 120GB.Thats a few more games.