There is no wiring difference on the tubes. The Two Stroke is really flexible that way. You can use the 6V6, 6L6, KT66, etc. with no change to wiring or bias. The only thing that changes is the impedance, so you will want to make sure to match it via the switch in the instructions. That same switch will allow you to use either a 4Ω or 8Ω load so I wouldn’t recommend omitting that switch. Though you could if you were going to lock down a certain output configuration.

I will post the impedance “chart” on the wiki page so that it is easily accesible.