Greetings to the Brain Trust!

I purchased a well used 2005 Silverado specifically because it had an L33 in it. Having a working engine, transmission, computer and harness sounded like a good idea and its currently filling a necessary need. The engine and transmission will both be completely rebuilt before going in the Jeep so NOW is the time to start putting my plan together.

I'm a big fan of the original 327. So much so my 1959 Chris Craft has one that replaced the original 283. I also figured the 5.3 would be better on fuel AND I don't need the power of the 6.0 or 6.2 in my Jeep. 100HP over the stock I-6 195 will be an improvement and I don't want to blow up my Dana 44's on purpose. So now you know the WHY behind my engine choice for the Jeep. I also plan on installing the 4L65-E.

I have been doing a bunch of reading and watching on the Gen III engines. Recently I came across a number of videos and posts recommending the 862 heads for the 5.3 over the 799 heads that came on my L33. The logic is solid considering the lower displacement engine doesn't need the increased head flow of the higher displacement engine. Also, my Jeep won't be seeing those high RPM ranges! So I'm going to source a set of 862 heads, but I have questions. My target horsepower is 300ish.

HEADS: Should I keep the 1.89 intake or open them up to 2.00? Fuel economy is important and the engine will rarely see 5K RPM.
INTAKE: I'm keeping the stock truck intake. I don't need the extra flow of the TBSS.
PISTONS: Keep the flat tops the L33 comes with? I'm thinking yes.
INJECTORS: stock
IGNITION: stock

CAM: Here is where I'm completely lost. The L33 intake and exhaust share the same exact specs! I've never seen this before. I need a cam that will work good with the 862 heads, flat top pistons, truck intake, CTS exhaust manifolds, give me about 300HP, and good as I can expect fuel economy from idle to 5500. I don't have a clue and could really use your wisdom. Thats all for round one. I eagerly await your responses!

 

So my .02 is this since you are going with a more or less a stock 5.3 rebuild is do just that just leave the 5.3 stock. Unless you do something crazy you won't tear up your Dana 44's.
I would go with a LS6 style intake/throttle DBC mostly because they look so much than a truck intake.
I have a 98 Wrangler with a mostly stock LS6/4L60E combo. I have 14 years on the swap and it has been bullet proof. 8.8 Explorer rear end with 4:10 gears. Stock 30 Dana up front. No issues. 241R TC out of a Rubicon.
My 98 Wrangler was a 4 cylinder originally so I went from 140 crank HP to 405 crank HP. Very fun to drive.
A few pics of the Wrangler. First two as the Wrangler sits today using 2002 Camaro BBK intake and FEA.. Third is when I built it the first time using a truck intake and truck FEA.

 

I have been looking at the Brian Tooley Truck Norris cam for the LQ4 in my TJ. Not sure how the CTS manifolds compare to the 2010 Camaro but they fit great on my swap. I have a build thread on here a few pages down. Post some pics!

 

In regards to the exhaust. I would suggest running some sort of block huggers. The reason is on the right hand side of of the TJ chassis it gets real tight with the TC and the front drive shaft space wise for exhaust. Best to run the right side exhaust tube around the front of the engine and merge with the left hand exhaust. I used 2.5" tubing left and right and Flow Master 2-1 merge with a 3" outlet. Then 3" to a large length wise 3" Dyno Max muffler. Then a Grand Cherokee 3" tail pipe. Except for the tail pipe I did this with a box of bends from Summit Racing.

 

When choosing components for your L33 Jeep project, pay attention to the optimal balance between power and fuel economy. Leave the 862 heads with the existing 1.89 intake valves as they are suitable for your purpose. L33 flat pistons will be the optimal choice. As for the cam, look for an option that will deliver the desired power at low to mid-range engine speeds. For more information and tips, visit https://jeepmodelsbyyear.com/. You can find a lot of information about different jeep body styles by year, which will help to make the project better

 

Yeah my TJ suffered serious project creep. The third pic is when I first built the TJ. It was a rust free Texas TJ that was a theft recovery. The engine you see in the third pic is a 4.8 with a AX15 5 speed trans. The 4.8 had a mechanical fan. That's 4.0 radiator/shroud in the pic. Worked well. Never over heated. Decent combo but I also plow snow with it in the winter. Got tired of shifting.
So I bought 2002 LS6 and 4L60E.
The paint wasn't great so I decided to paint it and then soon had the body off the frame so I could powder coat the frame and other assorted parts.
One thing I would say on the first pic is that the LS6 I used the 2002 Camaro front accessory stuff. It works well except when I put the plow on and the left upper control arm mount has touched the bottom of the alternator. I had to lift the TJ 2-3 inches. If I had to do it again I would use C5 front accessories. Moves the alternator up.
I will say it again its a great swap. My TJ is a true mall crawler. Never seen mud. I did have it on a gravel road once. LOL.
Snow pic.

 

The stock L33 with 799 heads is 9.9 compression and makes 310hp @ crank on stock tune. I'd leave it as is, put a good flowing exhaust on, and tune it. If long tube headers are available that would be a better use of your $.

If you're dead set on spending money on a cam, the SUM-8727R1 will make more power from idle to 5500 rpm than the stock camshaft with slight increase in fuel economy. It'll work with LS3 springs.

 

I hate to say it but I just don't see a long tube header fitting on the drivers side. You might be able sneak the left side exhaust up and around the transfer case but it's going to be super tight. May also may have front drive shaft clearance issues.
Small cam makes sense. But if I was going to upgrade the cam I would also upgrade the valve springs and push rods.
Scope creep. Isn't it wonderful?