Mike T is right........... you might consider a longer board for those pounds. With a shorter board you can make tighter turns, but you may go over the front if you're too short. I'm 6'3" and weight 220 riding a 173 Burton >> and sometimes wish for a longer board.
My first suggestion is to go into a local board shop and find someone who will help you transition to a carving board. They can help with equipment specific for your mtn.
Getting good instruction will save you tons of butt pain, and avoid injury.
Have fun. ML