Hmm, I think you could try putting in the stats on the IV calculator here:
http://www.psypokes.com/dex/iv.php
Say that there are zero EV's in each, and give whatever stat values the Snorlax has. You will then get an error message on each of the stats that are in fact EV'd(because the zero was wrong).
I don't think you can get exact numbers this way, but you can get pretty close, especially if it's 252/252. ^_^
Hope that helps. ~Zam