Just about 1.25 difference in overall height. If you plan on lowering it any/some more (if it already is lowered) they will give you more room for lowering as well as drop your truck buy the 1/2 height amount....The .65"

 

what about if i keep my 16s? any recommendations on what will be a good tire size..im going with a 3' 4 drop soon

 

I have 275/60-17s and a 3/4 drop. The tires are 30" tall. I wouldn't go any shorter on tires with that drop. And I would skip the 4" rear drop for a flip kit. I have quite a bit of rake.

 

Thanks BLACKND - that helps with my decision - I'm planning a 2" shackle drop in the back to level mine out and that's all... I'm going to try and find some 18's for mine though.