I just posted this link in another thread for a guy wanting to know how to pitch his Deere deck properly. Go to this link, then scroll down the menu on the left and click on "Adjusting the mower deck-all models"
Like I posted in another thread today, and the guy above said as well, make sure the area that you check this deck for level on, is dead flat. Whether it is on a slight angle (as on a sloped driveway made of cement) doesn't make too much difference, but whether the area is flat does ( I lay a 6' level out across the area in several different directions and look for obvious dips or humps that can be between where the tires will sit and under the deck, and can affect the measurements taken) If there are "birdbaths" or "knolls" in the cement or whatever you check the deck on, you can get false reading from your deck gauge or tape measure. I highly recommend the Deere deck gauge. They're cheap to buy, and I have been using the same one for many years now. They make checking pitch a snap.