How much horsepower does a 1999 z-28 have?

They have 305 horse. The SS had either 325 or 335.

It was underated at 305 horse power at the factory, but was actually closer to 325.

*** Depending on the trim, Z28 or SS, it made anywhere from 290 to 305rwhp for the Z28 and 305 to 315rwhp for the SS Camaro. ***