It's sucks to hear tuners and multiple people say the block needs to be sleeved at a certain power level to last yet people claim their engines make above that and are fine for years. Who are you going to believe. That is a rhetorical question. I have no idea. Go look how much it cost to sleeve a block then you are still stuck with 2v heads unless you spend even more money.
Having seen multiple people lose an engine trying to make big power and even more making 10-11 sex power with more sense and knowledge than me, I am going to keep mine around 550-600 (if that) when it runs again. I'll already have a J&s vampire so hopefully save it if it ever has some knock. I took off my killer chiller because it couldn't keep up with the charge temps. I also took off my meth because to me, it was just an unneed fuel source to fail.
If I had a stock block again, I'd do choppy cams with supporting mods with full exhaust. It would be for reliability, sound and fun, not going fast.
As for high hp 6r80/10r80 transmissions, here's a great video to watch to make you never want to attempt that unless you like braking transmissions:
The information for all of this is out there. Unfortunately it is impossible to know who to believe. Good luck on your choice.