J vs. D type overdrive

[GatesDavid@aol.com]

I just got a third car.  This time I'm really going to use it for parts.  My
hope is to get two of the three going within a few weeks.  Anyway, my question
is how can I tell what kind of overdrive is in it?  I plan on putting it in my
'78.  The new parts car is a '76.

Thanks,
David Gates
Hawaii
'73 Spitfire 1500 (Daily driver)
'78 Spitfire 1500 (working on this one)
'76 Spitfire 1500 (just aquired)
http://members.aol.com/gatesdavid/index.htm