I've ran two different level kits on my 2017 Sierra so far. First I purchased the Readylift 2.25" level with tubular UCA's which I ran with 275x65r20 Ridge Grapplers on my stock wheels. No rubbing and I was very pleased with the setup. After a few months I decided to buy aftermarket wheels and tires which were the Hostile Sprockets 20x10 -19 offset with 33x12.5r20 Toyo RT's. Major rubbing with the new wheels. I bought the Motofab 2.5" top mount spacers used from my friend and had a shop install those which took a lot of the rubbing away. Still rubs in reverse at full lock..very happy with the new look. The readylift 2.25" level gave my truck a slight rake which I liked. The Motofab 2.5" level gave my truck a totally leveled look which I've grown to like more. Attached are both setups.
First picture is the Readylift 2.25" level with 275x65r20 ridge grapplers on stock tires. No rubbing. Slight rake.
Second picture is the Motofab 2.5" level with 20x10 -19 Hostile Sprockets with 33x12.5r20 Toyo RT's. Minor rubbing. Perfect level.