Tire size and cold air intake

[xahtep9563]

Hello everyone,

I recently purchased a 2019 GMC Sierra 1500 SLE (new body) and
I'll be adding some mods and I'm looking for recommendations.
First, I'm getting a set of 18x9 rims with -12 offset and a 3" lift kit.
What tire size would be recommended given that info? I was planning to go with 275/70/18 but I afraid that they'll be too skinny..

Second, what do you think of the K&N 77-3110 kp cold air intake system?
Worth the money?

 

[Hawkman]

What engine, 5.3 or 6.2? I’m looking at the Roto-Fab CAI for my new 2020 SLT with the 6.2.

 

[Hawkman]

Did you decide on a CAI? I’m stuck between the Roto-Fab and GM unit. 2020 Sierra with the 6.2.