I've searched and searched and searched... I found lots of info, but no manufacturer for that 226W pelt. Anyone?
I did find out that the Gemini spiral block is actually 2" by 2", and that the hole spacing is 1.675" (aka 42.5 mm) which could accept a 40mm pelt, bolts not whitstanding...
http://www.geminicool.com/images/big_CADCPUSpiral1.jpg
I got a reply from Danny@dtek: He says he hasn't received too many requests for running a pelt with a spiral, but that the lexan top overhang is very strong, if I wanted to use it for clamping. He kindly reminded me to check my mobo spacing.
He also told me that he's expecting a new spiral in three weeks, and that it would make things easier...