A corsair TX550M? Yeah that should be fine an OCed 2060 wont pull all that much more power than it will stock. I run a 7700k 4.9ghz 1.27v with a 2070 super on a seasonic G-Series 550watt without issue.
Have you tired anything lower than 1.37v? That seems excessive for 4.9ghz on an 8700k. I would imagine that runs quite warm unless you have some stellar cooling.
Thanks for your reply!
It's been a long, long time since I did it, but I know I spent A LOT of time trying to find the sweet spot. And from what I can recall, it was the most stable voltage. Luckily, it's not had an issue since. My archived results of stress testing which I believe was on Cinebench scored 1606 on 80*C. Admittedly, I'm too scared to tamper with it anymore since it works great and gives no issues.
Edit:
Also, I don't know about "stellar cooling" but I went with Noctua NH-D15 and she does nicely.