The shorter belts won’t fit or help you if your car is still at factory spec.
The best mods are Intake (look for JWT POP Charger - you can get one for $100) exhaust and ECU. That’s a quick way to make your Z 400hp :tup:
If you do decide to get an ECU, don’t go with JWT. Check out www.ashspecz.com and order one from him. Much better and costs less.