gears benefit cars with upgraded cams. Requires dyno for dialing in the right combination of advance or retard. It just depends on what rpm range you want improvment on. You shift the torque curve when you advance or retard. You can also change valve overlap.
I will be selling my JUN cams and JUN valve springs soon cheap. Email me if interested. They have low miles of 5000 miles and have been polished and cryoed . They pull hard on the top end with little torque drop off like stock.