Tube Rolling ARC VTM 120

Anyone done tube rolling on the ARC VTM 120 monoblocks? They use 6922s and 6550s. I bought a pair of these amps used 6 months ago; they sound great, but I am considering changing the tubes as I do not know how old they are. I'm considering Electo Harmonix as I've had good results with their 12AX7 and 6550s before. Opinions ?