Hello performance truck people. I got a stock lq4 crew cab 6.0l 4l80e with true duals. And it's just a dog on the bottom end. I was considering 4.56 gears since the 4l80s 1st gear will take you to 45mph and 2nd gear to 90mph. Now I'm going the performance route before I swap gears. This is my build I have researched on for about 6 months.

Anyone got any good suggestions that would would alter my build for the better of towing/torque for bottom end thx

 

That cam will not work in an LS. It is for the old school SBC.

You need something smaller, I sing praises about the 212/218 but that may even be larger than you want for towing.

I have no idea why you picked the 706 heads, they are prone to cracking. You could mill the (assumed) 317 heads you have and they would work fine.

S&B intake is overkill IMO. I'd just do a drop in filter and the Airraid intake tube. That is probably enough.

It would be helpful to know what year truck you have.

 

Anyone know of any torque cams the produce power from 2000 to 6000 rpm I love to abuse the throttle daily. Would need to pass smog. It's an 03 chevy 1500hd 4x4
I was considering the truck norris cam but am unsure if I will be able to make it pass smog

 

https://cammotion.com/in-stock-ready...206-210-115-5/
I use this cam in DOD deletes and it does very good. Idles smooth as stock cam and makes good low end. Havent had time to do a stock dyno vs this cam on dyno with tune tho.
It made enough difference my wife noticed it when i did the 5.3 in her tahoe.

And the intake/throttle body wont make a difference. Airaid MIT tube and a Wix 46678 Air filter in the stock box will support 420rwhp without being a restriction.

Shorty headers dont gain anything but future exhaust leaks.

$800 for a fuel pump is silly. A Walbro 255 is about $100 and will support way more than your going to be making.

Id use 243/799 heads if you want to swap heads, keep stock rockers.

Iv used about 120 sets of these last year with no issues. https://cammotion.com/lifters/ls1-oe...16-d-12499225/

Then your going to need a tune so be prepared for that before tearing into the engine.

 

Since your poor choice of upgrades were already at $3500, why not go all in and get a supercharger? I saw CARB compliant kits on Summit.

And I'm on a mission to spread the word about shorty headers. I am a missionary. Power increases from headers don't come from increased flow, stock manifolds flow well. Power is increased by tuned length scavenging. Long tube headers tubes are of a length that exhaust pulses actually pull the exhaust from adjacent cylinders, which reduces pressure in the cylinder, allowing more fuel/air mixture in. Short tube headers are for engine swaps where the stock manifold's outlets are not in the right spot. They are also for looking cool in T buckets with a SBC swapped in. They also, to quote a very famous member of this forum, "dont gain anything but future exhaust leaks."

 

I'm famous? Haha
doubt that.
I've got to see all the good and bads of parts and swaps. Learned the hard way on several things with LS engines.

But I do agree. A carb compliant super charger would give torque gains off idle more than the list of parts combined would give at 6000 rpms.

 

And also cost at least double his current parts list budget...

But yes, that parts list posted has some flaws for the goals stated, you guys covered it well above. Superchargers are sweet... but laying down 5-7k (with no other supporting mods) is hard to swallow for most.

I haven't seen anyone mention the other alternative to throwing boost at your LS for towing... which is sell it and buy a Duramax or Dodge Cummins lol. That one used to get tossed out a lot.

 

A camshaft change and tuning are not C.A.R.B. compliant.

Some shorty headers are, but they are not worth $600 for nearly no gain....

I am not aware of any aftermarket LS camshafts that have received a C.A.R.B. exemption.

The only Modified tune that I am currently aware of that has a C.A.R.B. exemption is the one that you get with the Magnuson Supercharger kit.

If you want to be CARB Compliant, the Magnuson Supercharger kit is your best bet.

Technically speaking... You can change the gears, How ever if it causes a check engine light, You will not be in compliance. If you attempt to change the ratio with the aftermarket tuning software, You will no longer be in compliance....

 

The OP could move to a different state.

 

I initially was wondering OP was swapping to a "carburator." 🙈

Anyhow, I was going to suggest a regear before anything else. Does regearing to anything outside of what the factory offered still keep it compliant with state regulations? Or is that okay?