i recon he fought bute in the ams he can fight guys just as big as bute now...ggg just needs to put a bit of weight on, but height should not be a problem.. one thing most ppl over look with smaller fighters, is they have been smaller most their lives and have learned to adapt to fighting bigger guys...tyson is a prime example, he was very small for a heavyweight at only 5'10", so almost every fighter he ever fought was taller and bigger than him, rememebr tyson only weighed 212-220 lbs...compared to the heavies that are 240+...