Getting a higher cutting height w/ JD 265?

[Verticaltrx]

I have a 265 Deere garden tractor with the 46" deck. It has always cut shorter than I would like and with the dry weather we've been having it would be nice to cut a little higher. It seems like with the deck all the way up (in the transport lock even) it only cuts about 3" high. We used to have a 180 Deere (same 46" deck, smaller tractor w/ different lift system) and it would easily cut 4-4.5". What am I missing here? Or is that just the way it is? Thanks in advance.