Probably 1998 DOhC EJ25D kit but we don’t know what parts you have.
DOHC belt and match the tensioner to the bracket you use (single piece or two piece).
There are two DOHC tensioner styles, one piece is early usually 1996 and some 1997s, which is what HLAs usually are. Two piece is 1997+.
you don’t tell us what parts you have or if you have both complete engines.
You can use either tensioner style, they’re interchangeable. The tensioner bolts to a bracket so swap bracket to swap tensioner. Two bolts and $20 from Subaru or use what you have. Easy.
Probably use the 253 bracket and newer one piece tensioner since it’s a complete kit. Assuming you have the bracket too.or just buy it from Subaru they’re cheap
the older style kits only come with the pulley so if you don’t have the tensioner you have to buy a timing kit and tensioner.