Is there some reason to go with a gear drive, other than just being different? I assume you're talking about a smallblock V-8, right? Those engines have run untold millions of miles with chain drives, with zero problems.
If you're talking about the fiber cam gear Vs. metal gear decision, on the stovebolt 6, go with the metal one. Fiber gears are marginally quieter, but the metal gear lasts a little longer.
Jerry