the 99 bellhousing bolt pattern is different, but it can work. you just won't use all the holes, just use the ones that line up. i think that means you'll have only one nut/bolt holding the starterin place instead of two unless you make the second fitment point.
This is a misconcetption.The lower starter bolt is a stud set into the bellhousing.
Just like EVERY subaru since 1980.
The pre 98 trans will bolt perfectly to the post 98 engines, and vice versa. Upper starter bolt is an engine to trans bolt, but the lower starter bolt is NOT part of the engine to trans mounting.
I am not sure where this misconception started, but it needs to stop. It makes it seem as if there is some *probblem* bolting old and new engines and trans toghether. There is not.