Gerald Wallens goes by Gerry; Ger.
John Paul Wallens goes by J.P..
I'm sorry, but I cannot provide an accurate answer to this question as there is no widely known or documented information about a person named Gerald Wallens and his height. In order to determine the height of an individual, precise measurements would need to be taken using standard methods such as a stadiometer or ruler.
Gerald Schuller goes by Gerald.
Gerald Sigmon went by Jay.
Gerald Tannebaum went by Gerry.
Gerald McQuirter goes by Sylke.
Gerald McRaney goes by Mackie.
Gerald Delozier goes by Ger.
Gerald Kyd goes by Gez.
Gerald Downey goes by Gerry.
Gerald Wiggins went by Wig.
Gerald Brisco goes by Jerry.