This is something I've been wondering about for awhile. I have heard it's 1 inch from the top of the shell, but since no other dorel seat goes by the 1 inch rule, I wasn't sure if I could believe that. Today, at walmart, I noticed that the safety 1st aoe had the manual attached, so I read it. It is the rf to 35 and ff to 50 pound version. It simply states the rfing limit to be 35 pounds and 36 inches. Nothing about headrest positions, the shell, or any 1 inch rule. In the warnings section is says not to use the seat if the ears are above the headrest. So, what say you about the rfing height limit? What about a super tall torsoed 36 inch kid?