Elvis' hair - how long?

In the 1950s, Elvis Presley's hair was considered LONG, but I have trouble seeing it that way. Sure, the top may have been long enough to pompadour, but wasn't it short in the back? In order to look exactly like Elvis before he entered the army, how long do you need to grow your hair? Will it cover your ears when not combed into the proper pompadour?

I sometimes see guys whose hair looks like a sort of imitation of Elvis' haircut, but with a longish part in the back, so that when combed it looks almost mullet like (not very nice IMO), sort of like a quickie imitation of Elvis Presley's hair. I think however that Elvis wore it short in the back. Or am I not right?

As an interesting note, the film Grease starts with as little cartoon of the characters getting out of bed. Danny and I think also the other guy come out with enormous mops of hair, then grease it into Elvis styles, making what looks like long hair look neat and short. But of course, this is just the cartoon (and didn't John Travolta look great with hair like Elvis!)