Did Elvis have a lot of chest hair?

NO, Elvis did not wear a toupee.

Elvis had very fine hair, originally as a child it was blonde then as a teen it was "dirty blonde" which was a combination of blonde and brown and in later years his hair was gray, and all of his hair was real. Hence, no need for a toupee.

There are some pictures on the internet of Elvis wearing a wig but that was for scenes in Jailhouse Rock.

Good question by the way.