I don't think he'll have a problem with anything except CyberSpaceMountain. I'm 6' 6" and I've not had any problems with anything other than the simulator for CSM which was a very tight fit, but I was able to do it.
First visit: Disneyland, July 17, 1955 (well, somebody had to be there on opening day!)
Most Recent Visit:
WDW - Sept 29 - Oct 14, 2014
WDW - Jan 21-29, 2015
WDW - Aug 25 - Sep 5, 2015