When I had my tranny out of my car I found out it is a 1966 part.  I have the 1-2-D shift pattern though.  Did someone change the valve body of my tranny or what?
I can make the 1-2 shift any time I wanted.  I usually held it to about 5250 on my AutoMeter tach.  The 2-D shift would shift automatically at 5000 RPM though.
