If you need to know Hulst's date of birth you can find it for a few bucks at various sites. He passed away about 10 years ago, so his info is presumably online at Ancestry.com, which has social security info for all deceased persons who had a ss#. Also, google for birth records, again, there will probably be a subscription fee. Also, his long-time coach, Len Miller, is, I believe, out of retirement and working as a walk-on coach at Santa Barbary Community College... he might know.
Hulst was a phenom. The first year I coached he was a senior and one of my guys was running in the same 2mile CIF qualifying race. My runner's goal was to break 10 minutes (which, by the way he did!) and he was well aware of Eric's exploits and reputation. My guy happened to draw the lane next to Hulst at the start and, although they were the same age, he shook hands and said, "Pleased to meet you Mr. Hulst!" Eric appeared to be at ease with his own celebrity status and was very cordial to my runner before and after the race. He was a good guy in my book.