I think this is a spatial relations type skill. Some people are born with the ability to rotate 3D objects in their mind, and others are not. As long as his spatial relations skills are at least average, I wouldn't worry. I have one who can visualize rotating and assembling 3D objects in her head, one who can't do this (but can see ahead many moves in stuff like chess), and one who is somewhere in between. All three are very bright kids (first two have been IDed as gifted, third kid is only 9 and we didn't get the others IDed until 7th grade).
