I cant find ONE tire with 38 inch with a 17 inch rim........

 

37's, 38's and 40's for 17 inch wheels.

http://www.procomptires.com/xt3plyapps.htm

http://www.mickeythompsontires.com/truck.html

http://www.intercotire.com/site25.php

HERE ARE 38" tires for a 17 inch wheel for you

http://www.intercotire.com/site34.php

http://www.intercotire.com/site35.php

Hope they help you out. Seems like these were all I could find. They are considered to be a pretty good tire. Good luck