New tubes question

[boogietone]

Awhile back I sent my MKIII in to Mesa to have it gone through. It came back with STR440 tubes. I have some STR454 tubes I want to put in it. Would the amp have to be rebiased for the STR454's to sound right? Or can I just put the tubes in and be fine since both sets of tubes, the 440's and 454's, are from Mesa?
Thanks!

 

[boogietone]

Mines only a 60 watt. So I don't have to worry about EL34 positions. Have you ever played a blue stripe? If so, how does it compare to a green stripe? I want to get another MKIII and I think I'd like to get a green stripe but I don't know how they sound.
Thanks for the info Rabies!