1972-1979 V8 Novas and their GM cousins (Apollo, Omega, Ventura, Seville) came with an 8.5" that bolts in without moving the perches. With discs, it's the same width as the original with drums. All I changed was the u-joint and shortened the driveshaft. Held up fine behind the 455/400 (275s but not slicks). Many people run them as-is deep into the 11s on slicks even with a manual. If it dips into the 10s I'd recommend a girdle cover, and fully welding the axle tubes. Faster than 10s, you should probably switch to a 12 bolt or 9".
