I agree...there's no such thing as too tall. So, go after the competition man!
You might find that you need more mass if you're competing in a natural bodybuilding show. However, if you are competing in a men's physique show, you might find that you'll do really well. Your shoulders look naturally broad and you seem to have a good v-taper with your back already...it would just come down to conditioning.
Good luck, dude! If you do decide to go for it, keep us all posted on the journey!