What is the biggest size tires that I can fit onto my 2015 Ford F-150 18 wheels?

I apologize if this may be a common question on forums, but I'm new to trucks and the answers vary so widely.
I own a 2015 Ford F-150 XLT SuperCrew, and I was hoping to get larger all-terrain tires. I was planning on either getting the NITTO Terra Grappler G2s or the BF Goodrich KO2s. I currently have a leveling kit on my truck, so that should give me a bit more clearance on going up a few tire sizes. I was told by some F-150 company workers and they said that the biggest size would be 285/60-18. Is this true? Also, could I get away with going up to 285/65-18's or would that cause rubbing?

Lastly, which of the two brands of tires would you recommend for overall quality?

Thanks in advance!
Added (1). I came across suggestions of getting 35x12.5-18 tire. Would this size tire work, or would that rub? If it were to rub, how much trimming would need to be done for it to fit properly?

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