timing belt fitment

[peter]

So Im having my timing belt replaced along with a few other things but I just bought a water pump and timing belt from a friend for 20$ trying to save myself some money cause the shop wants over $230 for timing belt, water pump, and a few seals. My friend had them for his 92 (I think) Legacy 2.2 but scrapped it before he ever used them. The water pump will fit and I would think the timing belt will but online they are listed as needed different ones for the brand I have. It says I need a Gates T254 for my 98 Legacy 2.2 and my friend gave me a Gates T172. According to the OReilly website they have the same dimensions and number of teeth, and when I searched for other brands one part number was given for both years and many in between.

So will the one I have work? Seems like it should but then it doesnt make sense why there would be a different one listed for the different years

[Baddog]

I want to say the only difference is the belt tensioner?