around 95 - 96, calif. implemented emission standards, and other stuff, that were stricter than the rest of the US. (several years later the rest of the country caught up with CA.)
as a result subaru used a timing belt with a 105k mile interval. they also tweaked the computer to meet the emissions standards. prior to this change, 60k miles was the standard.
by 99 / 00 all US subarus switched over to the 105k interval.
however, in the asian market, or so i am told, all ej25 subarus have a 100k km interval and always have. that equals 60k miles.
at my local parts store, they stock the 60k belt, and you have to order the 105k belt. no real surprise there. but how about this, the 105k belt is CHEAPER.
it is worth noting that when they introduced the 105k belt in calif. they did not change ANY of the other timing components, pulleys, tensioner or water pump..