97 Votec 5.7 HP

['94Blackbird]

I have a '97 Z71 Silverado with a 5.7 liter vortec 350 and I would like to know what the HP rating is on this motor. Also my brother has a '99 short wheel base with a 4.3 liter and we were wondering what the HP was on that. He has a 5 speed standered and its 4 wheel drive what should he expect for gas mileage? Thanks anyone

[97sle]

The silverado is under rated at 255hp, most people think closer to around 280 hp, and the 4.3L is 190 hp. Not sure on gas mileage tho