I am pretty sure you cant buy a .456 gear for the smaller 8" ring gear, thus making it the larger one. I ran a 10 bolt for 10 years solid driving, and pulled literally thousands and thousands and yes thousands of hole shots with slicks at the strip and also all over town during the week. I never drove that car without giving it every thing it had and then some. That rear end was a good solid choice, better yet it was already in the car, like yours is. A 9" would be great, if you got the 1700 bucks laying around go for it. But if not use the one you got until, if and when it breaks.