I've been reading the 10 bolt articles and would like to know if I've got it right. The ratio is determined by the ring and pinion gears? So to change the ratio only these two need to be changed regardless of whether it's posi or open diff? The posi components can be added to the existing ring and pinion gears with no other mods? Assuming the same family of parts. Specifically I've got a '91 V6 with a 3.23 open diff. What are the lower 'standard' ratios readily available for reasonable money? I want it for auto-x. What's the recommendation for posi components? As it's a V6 I assume the OE set up would be strong enough so what should I look for?

 

The gear ratio is the ratio of pinion teeth to gear teeth. The gears are mounted on a "carrier", which is either the open differential carrier or a posi carrier. Any gears can be used on any compatible open diff or posi.