overall wattage drop when using 6V6 in a Mark IV

[primal]

Anyone know what the overall wattage drop would be if using 6V6's in a Mark IV. I read the manual but it makes no mention of what the wattage drop would be.

I know you have to tun it in simulclass and tweed, but that's it.

 

[GD_NC]

I don't know the exact answer, however most 6v6 amps are rated around 8-10w per 6v6 tube. So, 35-40w??