dual boot - Common drive for Ubuntu 32 bit and 64 bit

I have searched askubuntu before writing this but was confused.
I have a hard disk which is having 320GB of space

Now I partitioned it like
78 GB for 32 bit Ubuntu
78 GB for 64 bit Ubuntu
160 GB for common space (I created as '/home' mount)
2 GB x 2 for each OS swap area

Now I have installed 32 bit in one 78 GB partition
But can not see other disk space.
I wanted to have that 160 GB space to share docs and other files

I didn't install 64 bit OS yet. Can anyone suggest me if I install 64 bit Ubuntu in the free 78 GB, will I get that configuration ?
My df -a gives this result :

and the blkid gives :

So will that do my purpose or I have to do something else? If something else then please explain what should I do.

fdiak gave this output: