The driveshaft was cake :-)
I called up Bob from KL Driveline again in Lansing, Michigan. Bob, for those of you who haven’t read other parts of the site, put together the Chevy 10-bolt that’s in the Talon. I asked him how to measure the driveshaft, and he told me to measure from the reasr diff yoke flange to the transmission output shaft. Cake.
6 days later, I had an aluminum driveshaft that bolted right in. See? cake!