Level/Wheels/Tires with 3.08

[Blue Line]

Hello everyone I recenty got a new 2014 Silverado CC LTZ Z71 with the 5.3 /3.08.

 

I wanted to level the truck and change the rims out to Fuel Kranks (18x9) and upgrade the tires maybe to a 288/65/18. I've read some concern on the truck being sluggish with the 3.08.

 

Will there be that much of a noticable difference? What would the cost to change the rear out, would it even be worth it?

 

Thanks for the input

 

Jeff