5 disk forward drum

The C6 trans I took apart has a 4 disk forward drum without the wave plate, so I have a 5 disk coming. Will the planetary from the 4 disk drum work in the 5 disk drum or is there something else I need to change?

the planetery is the same but you'll need a '76 and later ring gear and hub as the torrington pocket is deeper in the drum .330" vs .400"
Frank

I have a couple other C6's laying around. Is there a way to determine what year they are without opening them up?

look at the casting RF # on the drivers side of the case ,look for RH D7AP is the '76 and latter syle