ID Rear End Help

I'd look for a 68-70 B body 8 3/4" axle. The 8 1/4" is tough enough for the small blocks and even mild big blocks. Anything that will see some hammer time will benefit from a more durable axle. Also, chances are this axle is a one legger. Why add Sure Grip to an axle that was never put behind a 440 anyway?