mine reaches an inch or two below where my waistline is. i grip about 6" out from my shins, keeping my feet slightly closer than a shoulder's length apart.
squat all the way down in front of the bar, and, while keeping your back tight, lift the bar up. it is important that you keep your entire back tight and STRAIGHT when lifting. i've seen many people cheat their way to 275 in deads, but their backs were more curved than st. louis' arch. when you keep your back straight, you place a majority of the load on your back (not the spine).
when you perform them correctly, you should feel it mostly in your middle back.
where is the pain you're experiencing?