assuming you're using a 4MHZ crystal, it shouldn't be that bad, Higher than 4MHz... you'll need to use the according DEFINE and configuration fuses.

Assuming you have a PAUSE 500-2000 at the top of your program, you could still tweak it a little bit and change the value of those DEFINES bellow
Code:
DEFINE LCD_COMMANDUS 2000 ' Command delay time in us
DEFINE LCD_DATAUS 50      ' Data delay time in us
HTH