I don't think the perfect IV's follow on to the offspring, in the games you had to have the pokemon in the daycare hold a
power item to make the IV of that certain item to transfer from the holder's IV to the offspring.
Just to make things clear, if you just want a Larvitar, then don't bother with this, and if you DO want a perfect Larvitar, then you will have to wait for the next time Larvitar appears in the daily pokemon competition.