Help: Tube roll for Cary 120S

Hi all,
I would want to try tube roll on output tubs (8) of my CAD-120S
My question is do I have to find matching octet or just quad/pair ? If so, how do I match them
Thanks in advance
Try to go with "matched" quad pair.

Explain to the vendor you need a quad pair and they need to be matched for one amplifier. For example, I have "matched" quad pair of Genalex KT88 for my two MC275s.
Buy them as a matched octet matched from a pro vendor. e.g. Jim McShane, usually matchees as far as can tell for each tubes total emmisions. I gather that he really matched them in circuit by there bias points as well maybe not. He put the values of each tube which ranhed from 90-92 on each tube. I tried to assort them evenly in quads.It worked out very well.
Here's Upscale Audio's process for tube testing, burning and matching. Kevin even has a 90 day warranty on his tubes. The customer service is hard to beat, and should a tube fail, down the road say a year or two, he can provide a tube that matches the ones you have left. (