[6pack] A-Type O/D Issue

[Glenn Franco]

Hi
I'm having a $!X?!! of a time installing our rebuild A-type overdrive to 
our transmissions output shaft.
Numerous attempts to line up the 2 female splines in the O/D have 
resulted in zero success.
Every time I line up the splines they move out of position any time the 
trans is installed.
It's hard to line up these splines after the overdrive is assembled and 
it always moves out of position as soon as it's all put together.
Now we have a broken adapter plate.
I do not have a dummy shaft so that is out.
Any suggestions on a successful procedure?
Thanks in Advance
Glenn