not sure what you mean but, Toyota has been trying with different motors, and so far this season it seems to be working really well.
Yes they do have a version of power steering.
950 horse power
381 stock hp according to Toyota.
108
200hps
106 horse power if EFI
116hp stock
381 Hp
the nascar trucks cant go as fast as the cars can because there different areodynamically... they have the same amount of horse power and everything they wiegh the same amount just different areodynamically.
In the NON restricter plate races, they produce around 750 hp.
the mark 4 has around 360 hp
381@5600 rpm