My Engine builder will not use gear drives anymore either. They have shown on the dyno to cause more harmonicis in the valvetrain than a chain. Spend your money of a good double roller timing chain with torrington bearings behind the cam gear.

Another case in point, My friend built a 496 this year with a gear drive. it lasted 3 passes and caused him a huge failure.

Up to you, but i will never use one.