I'm throwing together a 2003 5.3 with flat tops, a btr stage 3 truck cam, ported 862 heads, tbss manifold and throttle body, and of course long tube headers.. I was wondering what kind of flywheel horsepower I could expect out of this?

 

Mid to high 300's for sure at the fly wheel.

 

I would think more, I don't have heads or such an aggressive cam and I make 302 to the wheels through 4.10s and 33s

I'd expect 350-360whp

 

What all do you have done to your truck? my goal for this is just a 400hp flywheel build

 

Im there now, if that's your goal. The extra compression, worked heads and aggressive cam ought to be worth another 30-40hp

LS6 springs
TSP 212/218 .550 "Stage 2"
4" ebay intake
e fans
speed density tune
TSP 1 7/8 LTs
3" Y
3.5" back

otherwise its a stock (rod bolts included) gen3 5.3 with 706s, dished pistons, stock intake manifold, stock TB engine

 

search for the BTR truck cam shootout versus stock on YouTube

 

I made 325 with a sbe 5.3, milled 243 heads, btr stage 4 truck cam, 1 3/4 long tubes, through a 4l60e (before it blew) , 4.10 gears on a 29 inch tire

 

Im runnin 4.8s with shaved 243's and ls6 springs , tsp cam and full bolt ons ,efans, hp tuned. When im on it my duty cycle is high hits 90+ real quick. I heard the stock can support over 400
Haven't been to a dyno but my *** dyno guesses 330 wheel. 4.11 detroit locker and 26.4 inch tires i hit 100 real quick

Front tires coming this week...im not squating on purpose.