Looking for info on tire size with my setup

[Arbucklek]

Hey, I'm new to this forum and I know theres a million threads on this topic. Hoping for a quick answer regarding my set up.

I have a 2018 Silverado double cab reg box with ready lift 2.25" level. (Gave me about 2.5)  I'm now looking to upsize tires while keeping stock 20" wheel. I know for sure the kit says a 33" tire will fit but what width can I go to on stock rim without rub? I attached a photo of my truck. 

 

Thanks 

Kyle

[youn1033]

Not trying to thread-jack, but I am hoping to find almost the exact same info, only 22" wheels and the level for the magneride. I'd willing to trim/pin back the wheel liner if necessary but have had a hard time tracking down the exact answer I'm looking for too. 

 

I am replacing 33 x 12.50 Nitto Terra Grapplers but it looks like I could go a bit bigger, especially if I got a slightly narrower tire.