I've done this same swap to a '76 so I can give you some pointers. The motor mounts on the frame remain in the same place, you will just need the metal "shell" engine bracket(motor mount cup) for a '75-87 SBC car. Truck mount cups are taller and won't fit correctly. Trans behind the six is more likely to be a TH250 (mine was) so look at it close. A TH350 will bolt in its place with no trouble. The six cars frequently came with the spindly 7.5" rear(mine did), but the V8 Nova or Camaro/Firebird 8.5" rear is a bolt in. The 7.5 is easy to identify by the two 3/8" long "fangs" that stick down from the casting below the rear cover at about the 4 and 8 o'clock position. The 8.5" will have a 1", square cornered 1/2 block at the same spots. Distributor and alternator wiring will need to be re-routed, and the power steering pump will need to have it's brackets changed to V8 type. Alternator and starter can be re-used, you might have to change the throttle cable. I was building a street/strip car so I left the sixer front springs in, and it did sit low with a V8. Sway bar was the same as a V8 car, if you want a bigger one look to the '70-81 Camaro/Firebird. The rest (belts. hoses, etc.) is stock V8 Nova. It is a pretty easy swap, done in a day if you have all the parts.