I was wondering what the converion for a 78 14 tire is off a trailer? I can not seem to find the site that had the conversion on it for trailer tires. Thanks for the help.

It's the old sizing for 78 series tires, meaning an aspect of 78% Much like a Q78 swamper, or the old P78's I had on my truck years ago, which were around a 31x10.

About the closest to a H78-14 is a 225/75-14

EDIT:
just searched, and found a pretty good site here..

http://carnut.com/specs/tires.html