Stat Evaluation

Usually I evaluate stats with this site, and use an appraisal to determine the exact IVs. However, sometimes that fails, particularly when Stamina is the highest stat. In that case, I put the mon in question in a gym and use Gymhuntr's gym history to get the stats.

However, I now have both a Groudon and a Kyogre with very good but uncertain stats. What's the easiest way to determine what their stats are, since I can't stick them in a gym (and wouldn't want to if I could)? Any advice appreciated, thanks in advance.