depends on which year. I do know it was posted at about 285 (same as the 5.3 from the 2003) in 2004
I believe it is 260 horsepower.
The horsepower of a GMC Sierra is 355 hp.
vortec 454,1996 thru 1999-->>>290HP 410TQ
397 hp
About 190 H.P.
215@2800. Rpm
197 rwh stock
The 8.1L vortec comes stock with 330 hp and about 450 pound feet of torque.
The Vortec 5.3 Liter V8 engine produces 295 horse power.
300 hp
145.
It has 275 hp.