Run_it

I recently purchased a 2015 Silverado 2500hd gasser with 115k miles and I don’t know if the previous owner changed the trans fluid/filter at 45 and 90k as the owners manual recommends, does anyone if changing it at this mileage will negatively effect my transmissions performance?

I have a 2015 Silverado 2500hd and recently purchased a set of 33x12.5r20s on 20x12s with a -44 offset, I put them on and rubbed a decent amount even with the torsion keys cranked up a ways. I didn’t like how it rode so I turned them down and put stocks back on for the meantime, I did some research and was thinking of putting on either the kryptonite stage 3 leveling kit or the cognito 3in leveling kit. Has anyone tried running a similar setup or have any info on how much or if it will rub?