As luck would have it, I found the point of repetition in Universe 3/03. You can find a full write up (DigTrig) on the topology of a cellular automaton using rule set 3/03 on a field that starts empty and is 20 x 20 in size. In short, 335,225 unique patterns with that final unique pattern looping back into iteration #243,830. Far less than the 36 quadrillion possible patterns, but 1/3 of a million iterations is nothing to sneeze at... about 35 Megs of text files! One note of interest: the number of unique iterations before the point of repetition, I called them "Prime Iterations", is 243,829... which by sheer chance... is a prime number! I guess "Prime Iterations" is a good term after all. ;)
Such a nice feeling to have defined the Universe of 3/03 and to know it's entire timeline and topology. I'm feeling a little omniscient. :D