It should...he'll have to have either the Pacesetter h-pipe adapter kit to bolt the GT catback up or have a shop fab up some piping from his cats/midpipe to the catback. The fitment should be the same though...All the stock piping for 94-04's was 2.25" and the overall vehicle dimensions weren't incredibly different.
I'm surprised you still have that catback lying around
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB