This is probably not your guy:

Floyd C. McCarty, b. 4 Dec 1894 Shelby Co., IN
Registered 5 Jun 1917 Shelby Co.

If you think it's him, send me an SASE and I'll
send back the image of the registration card.

Wes Groleau
615 Glenfield Drive
Fort Wayne, IN 46825

This was found at Ancestry.com by searching for
Floyd McCarty, b. 1894, all states. Note that they
apparently have not imaged AR or LA. I think we
have them on Microfilm here at ACPL but I do not
know whether there is an index.

I also tried McCarthy but there was no Floyd.