I'll throw this out, because it's relevant,.. are you thinking of doing tested shows? Obviously guys stepping onstage after passing poly's and urinalysis tests are going to weight a bit less than their counterparts.
In most tested feds, heavyweight classes are 190 lbs +, and the competitors are usually 5'11 - 6'2 or so. Admitedly I havent seen too many guys carrying over 200 lbs in contest shape, even in the heavies. THe few who have weighed in around 215 or so (and closer to 5'11 in height) usually land in last place due to their smooth conditioning.
I would GUESS, that you would need to be at least 210 in contest shape, and most likely you could be more than that if your structure allows. An old buddy of mine was about 6'2 and when he did his first show, he nailed his conditioning, but even he'd tell you that he needed more size to land a top spot.
And yes, true "contest conditioning" is something that very few gym rats understand until they're really been through a prep, or even been very close to someone who has lost 20 lbs more than his friends all thought he would actually need to.