My question is to how much horsepower/tourque a 99 SIerra 5.3L gets stock. I have heard everthing ranging from 245hp-295hp! I have a few mods so i was just wonder what i could guesstimate up to. Thanks.

 

In stock form the 99s had 285 at the flywheel. I believe they dyno about the 230(+-10) range at the rear wheels. I dont know what kind of hp those mods would give. I'd guess a MAX of 20 rwhp.

 

99's came with 270hp.

00'-03' have 285 and 04'+ have 295hp.

Reason the 99's have less power is becuase of the cam. They came with a .466/.457 190/191 115.5 cam and the 00'+ came with the same specs cam, but with a 114lsa which gave the motors a 15hp increase. Don't know if the computer was also improved. The 04'+ got a higher flowing exhaust which gave them another 10hp for a total of 295hp. The 05's came w/ efans, but they are still rated at 295hp. These figures are at the crank though, but these engines are very underated.

Im not sure about torque but its around 330lb.-ft. Hopefully someone with more knowledge about this will chime in.

 

Well not so good calculations but it might work who knows? 15% off HP 20% off torque this is the drivetrain loss.

270-15%= 229hp
325-20%= 260tq (i don' really know if the tq # is right)

Thats guessing you shuld have anywhere between 220-240Hp

Some one with more experience might chime in (im not this smart this is the calculation my 14 year old does) so there are people with real experience.