Originally Posted by JARblue

But there are 2 types of each of those. A stock size and an undersize. I'm finding this out the hard way as it appears I ordered the undersized one by mistake.

I've recently come to find this out when I ordered the one I linked above. It is smaller than my stock pulley and I'm trying to return it. MA Motorsports posted in another thread (think one of their GB threads for it) that the part numbers on the ATI website have not been updated to reflect the stock size wet sump vs dry sump applications. MA has an internal part number for the stock size wet sump application pulley. I don't know if that is something that ATI stocks or MA has to get a group together before a batch is made. I have reached out to MA.