ATS 3.6 Rear swap

Good evening to all. I have a 2013 ATS 3.6 Premium rwd....just wondering if anyone has or has heard of anyone who has swapped the rear out. Just looking for a little more get up and go without doing engine mods or power adders.

I've heard theres like a 3.42 or maybe a 3.45 rear? Would it just be a bolt in and tune? How would I find one?

Don't want to go down the road of just swapping ring and pinion, been down that road and they never last, just want to swap out a factory rear basically.

Thanks!