727 HP loss vs 904?

[turbo66valiant]

Say, I have a turbo Slant that makes around 400 HP w/ a 727. Does anyone know the hp loss with the bigger trans. Any #'s. Thanks.
Ryan

 

[70aarcuda]

old car craft magazine said it 904 takes 24 hp to turn whereas 727 took 45

 

[jar84203]

How much power, if built right, could a 904 handle?