just a new guy here. I've had a 05 rcsb silverado 6 or so years now. I put a 2/4 on it right away now I'm going lower and even picked up a 01 ls1 to get rid of the trusty 4.3
feel free to roast me or send advice.

 

Welcome to the site

 

you'll kick yourself for years if you don't just bite the bullet, spare the $, and cam the engine while it's out... ask me how i know
and ditch the car intake for the NNBS version

and if you want it to be a little snappier, throw a set of 799 or 862/706 heads on while you're at it they'll raise compression to high 10s.
welcome to the site - we're good at spending your money

 

if I cam it wouldnt I have to upgrade the valves and whatnot? the motor runs great right now very healthy.

 

usually a good idea, depending on cam size. some of the milder cams can easily use LS6 springs, which can be had on the cheap.
the reason i mentioned swapping intakes is because the truck version flows a bit better on the bottom end, making more torque that your truck will appreciate due to its size.

 

I deffinatly have the truck intake on. another question is the harness that came on the engine is for an automatic trans and I have a manual.do I gotta buy a whole new harness from painless ?

 

nope. can't remember the guys in FL i sent mine to off-hand (you could probably dig up my thread on here or ls1truck), but they essentially just pulled all the auto stuff out (but did forget to add the clutch safety jumper wire in the fuse block, which wasn't hard for me to do afterward).
for some reason, i didn't trust myself at the time to figure it out, but i'm pretty sure it's something i could've done given some more time & patience... considering i was swapping the engine out myself with hand tools

 

current performance wiring