Thanks Jake for the reply. Yup! A little too late. My lower race was definitely too big to fit through the lower clamp. I assembled everything losely, and then proceded to tap the bottom of the P321 steerer with a plastic mallet till the bottom race was fully seated. As I understand it, Craig from Mendon CycleSmith also did an assembly late last week, and used the same method. Its all together now, and though I haven't had the chance to ride yet, I like the setup alot.
I went with the new Lefty Speed Carbon SL at 110mm travel, and the Reba I took off, which I thought was set to 100mm travel had an axle to crown length of 485mm, and the Lefty is 468mm. So not only did I pick up 10mm of travel (though I never saw more than 90mm or so with the Reba), but I also somewhat restored the OEM geometry of my Giant NRS frame (meant to be used with an 80-85mm fork).
Jake, I'd love to see a full carbon version of your steerer to satisfy the weight weenie in me.