Thought I saw this in a post but I was wrong so I figured people would be curious.
From what I've read and talking to people that made the turbos; the stealth 64 and DTS old 64 used a box stock borg warner 7+7 cast compressor wheel that had a sleeve machined to take up the space difference between the size of the stock IHI turbine wheel and the larger diameter that the S300 has.
Being DTS's current 64 is billet I would assuming its got the correct bore that the stock IHI turbine is.
Yellowchevy