....

 

It's really all personal preference and how you want it to look and what size tires you want. I went up 2" in front and left the rear stock and the truck sits level to the eye but if measured actually is still a pinch higher in the rear. A lot of guys like to have a little rake specially if they tow/haul things so just depends how you want it to look and what you will be doing with the truck.

 

I have 275/70/18's on my pickup with 2 inch level in the front and stock rear. It fills the wheel well nicely with no rubbing since its a narrower tire. I leveled mine to remove the rake since I do almost no towing with the truck and its all for looks essentially. fx4freak hit the nail on the head, you have to decide what kind of compromise you want to make. I think with the 2inch setting and the new block you will have a bit of rake.

 

The difference in performance and strain between the 1" and 2" setting will be negligible. So basically that just leaves the look, which is up to you. I'd personally recommend the 2" setting as it'll give the tires more room to flex.