Stumbled across this when I was looking for hime (hyme also hits big) joints.
http://www.nwspeedequipment.com/ http://www.jackschoenrock.com/pages/tri-power2.html Some nice progressive linkage sets. Waiting for answers back for application to the Offy 3x1.
And last, a nice page on the operation of the progressive carb setup
http://members.aol.com/YBLOCK/progressive.htm John C.