4/6 DROP ON A 09 CHEVY CREW CAB

I WAS TOLD THAT DROPING MY O9 CHEVY WITH A 4/6 DROP WAS NOT GOING TO MAKE IT LOW LIKE MY 01 CHEVY WHICH HAS AN 4/6 DROP. I WAS ALSO TOLD THAT MY 09 WILL BE HIGHER IF I GET A 4/6 DROP ON IT AND I NEED TO GET LIKE A 5/8 DROP SO IT CAN LOOK LOW. I WAS WOUNDERING IF THAT IS TRUE?  

take a measuring tape and measure 4 and 6 inches lower than your wheel wells sit now.  not low enough?  bag it!