It should be a smooth go but without listing your full specs like motherboard brand, RAM brand/type/speed, etc. Any comment is moot. Just an educated guess would be "yes it should work with no additional settings". They take the same FM2 socket.
If you're planning to OC, expect lower peak core frequency with the A8 due to more cores. However, since it has twice the threads and 4 times the cache, overall benchmarks will improve quite a bit going from the 2 core to the 4 core.
"It worked before you broke it!"
