the automatic B16's only have single valve springs on both intake and exhaust cams, as well as weaker cams. they are made to have a lower rev limit, which was around 7500 if my memory serves me correctly. I had a friend with an automatic b16... he put in a "MUGEN SPOON NO REV LIMIT +20HP CHIP L@@K W@W" and revved it to 10k rpm (dumbass).
he broke one of the weak stock retainers, and dropped a valve into one of the cylinders at 10,000 rpm and completely destroyed the entire engine.