chevy silverado drop kit help. 4/6 and 5/7

I am looking to buy the 5-7 drop, but what is the differentce?
 
i understand the 4/6 comes with lower arms and a rear flip kit, 
 
and the 5/7 comes with upper arms and lower arms, do the upper arms really give you a 1" drop compared to the 4/6 drop kits?

 
im looking at DJM AND BELLTECH KITS.