Ultimately you want to run the gear that gives best quarter mile times for the strip part of your car, minus how much your willing to sacrifice for street. That's a you call, first I'd figure what the best gear should be for the track then if that's too deep for ya decide on best compromise.
You built an engine that makes peak power at 6500 rpms so peak torque is probably around 5000 rpms basically the beginning of your main powerband. If you want to access that powerband you got to gear it so you can reasonably access it at various road speeds.