Cary CAD120S: Please help on locate tubes position

Hi all
I have a nice pairs of 6SN7 tall boy and wonder which tube stage is best use for these tubes (driver or input?)
And which ones are driver tubes? Front-Rear or Left-Right ?
hello i think front-rear
Cary Audio
Phone: 919-355-0010
I was told by Cary front and rear make the most difference.