5.3z71

im new to these ls motors but im rebuilding my 5.3 in a 99 z71 and am looking to get a few more horses out of it, i am going with some full length headers, a head port and polish, a comp xr265 cam and a dyno tune. should i go with an ls6 intake manifold or keep the stock truck intake and port it? any help would be greatly appreciated.

camsshaft

ls6 is better for top end. In a truck though it may be better to keep it for the torque...? Maybe someone who's done in it and dyno'd can chime in...? IMHO i wouldnt go through the hassle of it if you aren't raising compression or planning on doing a valve spring kit and revving it out much higher. Thats just my opinion though. Interested in your results either way. Good luck!

5.3z71

thats what i was leaning towards, im not going to be going over 6200 rpm and i dont want to lose my bottom end torque. i am however swapping out for some ls6 springs to get enough lift for the xr265 cam. the dyno specs i found for a ported stock truck manifold only showed a gain of barely 10hp where the ls6 is nearly 20. but again i would lose my bottom end torque so i think i am goint to try the stock manifold first and see what it pulls on the dyno. i will post the info soon as i find out some more

5.3z71

any tips on a good way to port the stock plastic intake? ive seen a company that will do them but it looks like they actually cut them apart to do it. as always there is a lot of unecessary mess inside them.