So did Aston Martin, RollsRoyce and I believe also Ferrari.
Yes they were all TH400's (called a ST400) from 64-66 behind the Nailhead, with the two speed being a ST300. The 64 was the first GM car to use it and they hid that it was a three speed by only putting 2 gears on the shifter. You rocked the shifter back and forth to get into low gear.
Moose,you have a private message.