About how much rwhp do I have on my 99 5.3L Sierra (stock 3.42 limited slip rear end) and also about what would my 1/4 time be? I have currently installed; K&N FIPK, HPP3 (93oct. tuned), Edelbrock T.E.S. headers, custom ram air in-take, true duel custom flowmaster exhaust. All I need is a round number where I'm at. Thanks a lot What is stock RWHP for a 99 5.3L?

 

99's had 270 flywheel hp. You are around 235 to 240ish maybe. I could be way off here though . My 2000 was dynoed on a Winpeg Dynojet. I only had three mods at the time. I had a Diablo predator, Upd intake, a single 40 series flowmaster at the time of the run. I dynoed 246.6 rwhp and 307.2 rwtq. on third gear pulls.

 

Yep, I agree, probably in the 240 rwhp range.

 

My 99 pulled a whopping 218 HP 245 TQ with a Flowmaster muffler and Hypertech.

Before and after 01 LS6 cam. http://z71.net/camdyno.jpg