94-01 LS exhaust components are interchangeable with the 00-01 GSR exhaust components.

If you ordered a turbo kit for a 94-01 B18B1 for a 00-01 B18C1, the downpipe would line up correctly, but the intake manifolds are different, so the charge piping would have to be modified. The year specified on the turbo kit also could be due to electronics. 2000 is the first year for OBD2b on Integras.