I considered a geardrive for a moderate 496. Reading all the posts over time I concluded 1) gear drives are best for medium race RPM engines with really stout cams say up to 7500 RPM 2) At really high RPM a belt drive is better... the gear drives can create/transmit their own harmonics 3) At my level there was little benefit to a gear drive. 4) The Pete Jackson type has several drawbacks. I ended up buying a good $100 chain - .010 short to fit to my line bored engine - and saved the $3-400 extra for a gear drive.