Spindle And Tire Lift Question

[rxm6]

Truck is 2006 Silverado 1500, 5.3l, 3.73 rear

 

Looking to do a mild lift and ran into a Rough Country kit that has a 3" spindle for the front and 2" blocks for the rear. I've tried searching and haven't really found any information on spindle lifts, i.e. drawbacks, problems, etc. So I'm wondering if some of you guys can provide any insight on a spindle lift.

 

Also, with such a mild lift do I need new brake lines or any other extras I'm not thinking of? Alternatively, shocks on the vehicle currently have about 10k on them. Anyway to use them until they blow before putting on the ones that come with the kit?

 

Finally, would 285/70/17 put any great strain on the drivetrain or suspension? Stock is 265/70/17.