Saw some interesting things at nicklin auto parts in guelph today,
E34 530 w/ manual 5spd trans
E34 540 w/ manual 6spd trans
Old 635 w/ m30 and 5spd trans
I know these transmissions are harder to find and the owner said they generally charge like 150 for a trans if they pull it, and they'd be quite a bit cheaper if you pull it yourself.