Preamp tubes don’t need biasing adjustments. The four 6H30 for the audio circuit should ideally be a matched quad, in which case put them in any which way. If you have 2 matched pairs, ask ARC for guidance on the best layout to deploy them in. If you don’t have any matched tubes here (matching within ~ 10% on mu and Gm) - you should have bought a matched quad :)
The power regulator tubes are both singles, so just put them in.