You will need a Skunk2 or equivalent manifold and the LS kit to directly bolt it on to your application due to the differences in downpipe length between the 94-99 GSR and the 00-01 GSR. The LS downpipe will be the same length as the 00-01 GSR downpipe, so you just need a manifold with a higher port entrance to accomodate the LS upper charge piping.