I'm going to check the tire pressure. That's the only thing I can think of why it was 1/2 inch off. I know that a pound of air or so can really make a difference.
To adjust there's just two bolts to mess with on each side. One you loosen and one you turn clockwise to raise and counter clockwise to lower. If its the tire pressure I bet that I raised it and didn't even need to adjust the deck 1/2 up. If its not the tire pressure.
-1996 RAM2500 Cummins 12V
-Gravely Pro turn 52in w/23hp Kohler EFI
-Gravely pro hydro 36in walk behind
-Toro proline 21" suzuki two stroke
-Homelite hedge trimmers