I emailed them,, turns out this is the set up for a 3/8" deep slot...
Nick
The arbor to use is A210
http://www.woodworkersworld.net/ball...rs.shtml#arbor
The slot cutter is 6709C
http://www.woodworkersworld.net/slotting_bits.shtml
At the bottom of the slot cutter web page is a list of arbors and bearings for the different depths.
The bearing is B25
http://www.woodworkersworld.net/ball...s_arbors.shtml
They are all in stock
Thanks, Alan
Good stuff!