[Amps] TL-922 without modification

[Szegedy]

Dear Friends!

1.I have a TL-922 in original state,no any modification .Linear works ,but is it a probleme if I use it without modification?
2.Which is the the most important to modify? I red on a forum :filament voltage is too high?How is it?Kenwood made a mistake?
The line voltage is 220V in my QTH,my linear is set to 220V now,but it is not good for a tubes?
What about if I dont modify the linear inside but I set the lnput voltage terminal board of TL-922 to 240V ( with shorting bar at the rear of linear )?Will it be better for tube(longer life of tube)?
Lower filament voltage will be?But lower power out? How much? Not 1KW ,only 900W will be?But much more tube life? Kenwood made a mistake?

                                                    Thanks:Laszlo  HA5BZR