I've been lurking and reading for a while here, and I'm finally to the point of having my motor put together, but am unsure of what kind of power it's really going to make, i've heard alot of different things, but figured the crowd here would probably have some good answers.

First off, this isn't going into a truck. It's going into a dual sport rock crawler/desert ride, being built for a race in february called King of the Hammers.

The motor started as a 99 4.8l. I have not pulled the head's or done anything to the rotating assembly. the compression test was great, and even across the board. and only had 1 cyl leak oil past the ring's sitting upside down on the stand with oil on the bottoms of the pistons overnight.

I was given an LS2 intake, with injector's and Fuel rails. I have a 90mm cable operated throttle body for it. and the cam that i was given to use is an intake 294 @ .552 and exh 304 @ .568 with 118 degree lobe seperation.

What kind of HP numbers am i really looking at getting, using a remapped stock computer with a stand alone harness?

 

A stock 4.8 with the bolt ons and a good tune can get close to 340-350 "smog legal" at the crank. So even with the different intake you'd be sitting about the same just moving the HP up in the rpm scale.

I would stick with the tuck intake to keep my torque up, and add long tube headers with no cats. Then maybe you could pick up a 15 more horse if you delete the A/C and Pwr steering too.

Its all rough becouse you can do everything to a motor and not get more power beyond a certain point.

Also new motors are rated with all the accesories, and are you really going to use those in a rock crawler?

 

There's no way to make a truck intake fit the chassis, i had to convert it to can F body pan, balancer, waterpump etc. then build a bracket to get the alternator up in front of the right head, while the PS pump is attached to the right head.

My other advantage is it'll only weight approx 3400# and the TH350 auto rob's alot less HP than the bigger OD tranny's. my downfall is the 4.88 gear's on 39in tall tires.

 

well you could at least get the LS6 intake. That's good for 10-15 hp over the ls1 intake

 

I've got an LS2 intake, with a 90mm throttle body, it's larger than the LS6.

 

yeah but the ls2 intakes do not flow as good as the ls6's look at the top of this section there is a sticky with intake flow charts and an ls2 intake has rectangle ports not cathedral so It will not work on the 4.8L the only ls2 intake that will work is the one off of the tbss or ssr.