Putting a small block where a six banger once lived

What year car? Makes a difference, especially if it's an early A.

Easiest way is the Schumacher mounts. Keep in mind you'll need a lot more than just an engine. You need a new transmission, exhaust system, radiator, shift linkage, etc. I'm forgetting some things too.

Best way is probably to swap to a V8 K member, but that's a lot more work, and probably not a noticeable difference,if any, for most folks.

Keep in mind your /6 car also has /6 torsion bars, which were too small for the /6 let alone a V8. And you probably also have a 7.25" rear end, which won't last long behind most V8's. You may even have 9" drums in the front, which should also be swapped out with a V8. This stuff isn't mandatory to make the swap work, but if you want your car to safely handle the extra power, they're things that should be improved.