COPO part #s and a 9"

[Alan Roehrich]

Rod,
The only advantage a 9" would give you in your car is ease of changing ratios, and even then, only if you had spare center sections. A 56 Chevy Stock Eliminator car would not even come close to putting excessive stress on a good 8-1/2" or 8-5/8" 10 bolt Chevy, much less a 12 bolt. And any of those rear ends would absorb less precious torque and HP than a 9" Ford. The only limit to a 10 bolt for you would be that Richmond doesn't make anything lower than a 5.57 for it. If you need more than a 5.57 gear, you'd have to go to a 12 bolt. The upside there is you could use an aluminum spool in a 12 bolt, no one makes one for a 10 bolt.