Hello, new here and looking for some suggestions on my rebuild. Have a 2011 Sierra with a 5.3 lc9. Truck has 270,000km, just put a refurbished trans in it, truck is in good shape, so I don't mind investing in the engine and having the truck last for a while.
I picked up a used LC9 fully dressed and plan on rebuilding this on the side and swapping it in my truck sometime over the winter.
I'm new to LS, not to engine building, mainly BBC and a SBC 383 I did a few years back.
I'm looking to improve HP/torque numbers but having a solid, tough, long lasting engine is my priority.
I've been starting to research my options, and usually find forums are a great help.
From what I have been reading, the bottom ends are pretty good, just need to get the block cleaned up and can reuse my crank, rods and possibly pistons. I'm looking for a good combination of cam, heads, intake and possibly pistons to accommodate the larger cam.
From what I see, I can get a pair of AFR heads for what it would probably cost to have my stock heads cleaned up.
Been looking at the truck Norris cam kit, and a few others. The truck already has the DOD deleted, not sure if it was just programmed out with the same parts remaining inside or what. Just bought the truck a month or so ago and moved to another province.
Anyone have a suggestion on a combination that will make for a nice daily driver with a bit of kick?
I don't mind spending as long as it's in the right area. I like to do it right the first time. I will also have to find someone to help program and a decent machine shop in my area.
Looking forward to my first LS build. Thanks in advance. Ken

 

Don't know enough about the engine, I'm aiming at a 6.0L
4L60E? 4.10 6L80E? 3.73

 

Trans is the 6l80 with some upgrades. I believe the rear is 3:73 but would need to confirm.
As far as I know it's a stock 5.3 and seems tired. Some oil leaking, some blue when cold starting, and a bit of chugging when starting cold.

 

Swapping heads and intake manifold is a waste of time and money. The stock heads flow stupid good, some of the best flowing LS heads out there. Likely are numbered 243 or 799 on the casting. Throw them in the parts washer and that's all you need to do. Buying a set of heads for over $1,000 or whatever they cost now isn't a useful choice of money when you are not trying to make 700hp to the rear tire.

The stock intake manifold also flows a ton of air and makes great horsepower and torque. It can handle more power than what a 6.2 makes, just for reference.

Clean up the engine, check the pistons for wear and if they can be re-used, just hone the cylinders and buy new rings.

For camshaft you need to spec it based on what torque converter you want to use. Everyone these days just says Truck Norris this and Truck Norris that but never provides actual cam specs on what cam they are thinking about. If you want to retain the factory stall converter you need to choose a camshaft that roughly stays around the 212/218 size and have the LSA be somewhat mild in the 112-115 range. That camshaft will give good power, drive great around town and still get decent fuel mileage.

The LC9 fuel injectors should support the power and the rest is down to tuning.

 

About the only thing you can do for actual "torque" is long-tube headers. Practically ANY mods you do, above all a cam, will cost a little bit of low-end torque.

FFDP's cam recco is the same thing I'd suggest. That's yerbasic "truck stage 2", available from any number of vendors. TPS & ws6store are probably the 2 best places to get it from. Get PAC1218 springs at the same time. Buy an adjustable push rod, and don't buy push rods until you have ALL the other parts installed and ready to go; MEASURE for the right length, and just buy a set. If your measurement comes out to needing 7.400" you can re-use your stock ones if they're still good. Check the ends CAREFULLY, especially the rocker end; they gall real bad in the cup in the rocker very often for some reason. A bushing trunnion upgrade is not a bad idea. Don't bother with "roller rockers". Needless to say you'll be doing away with DOD/AFM and VVT if your new motor has those (different years of that engine code got different combinations of that); you may need a valley cover, and some plugs, to do all that right. Details can be found all over this site and also ls1tech.com.

For that cam, a converter anywhere in the 2500 - 3200 RPM range is about right, depending on your preferences. Won't materially affect gas mileage butt will make the truck feel like it has about 150 ft-lbs more torque at a stop light.

Unless you have good reason to suspect that there's something wrong with the short block - REALLY WRONG, not just, "I wanna mess with it" - LEAVE IT THE HELL ALONE. Don't mess with the pistons or rings unless you have no other choice. When you pull the heads off, if the bores look good, DON'T TOUCH IT. A stock bottom end will handle AT LEAST twice the stock HP without breaking a sweat. The bores in these motors, or really any modern EFI motors for that matter, don't wear like they did back in the 60s; they'll go MANY hundreds of thousands of miles, if the oil is kept clean. Unless you're looking to get into the 1000HP club, there's no there there. Frankly, it's probably cheeeeeeper to go get a whole other short block, than to dink with boring, honing, pistons, etc. ANYWAY. This isn't the 60s anymore.

Bearings are a different matter. You can easily refresh those without opening a can of worms. Ignore the cam bearings unless they're COMPLETELY wiped out. For whyever, they usually look AWFUL in these motors, butt it makes no difference whatsoever. Again, there's no there there.

I'd suggest also, a new oil pump; make sure you put the right O-ring on the pickup. New front & rear cover, and oil pan, gaskets. Covers come with new seals already installed, and cost about $1 more than a gasket and a seal MAYBE, maybe even less, which is why it makes no sense to do anything with em other than swap em out.

Best thing you can do overall, is a TUNE. Even an untouched stock motor benefits in a YYYUUUUUUUJJJJJJJE way from that. Not so much that the factory "didn't know what they were doing"; rather, their tune has to work in ALL conditions and usage, and as such, is VERY conservative. There's ALOT to be gained by leaving out the construction site and plowing types of compromises. There are some pretty decent mail-order tune places for situations like this. It's not like you're the first person to ever have that kind of a truck and be doing EXACTLY this type of upgrades to it. What you're doing is a WELL-worn road, with LOTS of experience in the world, so the wheel doesn't have to be reinvented from scratch for it. A good tuner (Blackbear, PCM of NC, etc.) will have you send in a log of your truck's current behavior, make changes to your taste, and dial it in, probably get it perfect in less than 3 iterations. When I say "current", I mean, AFTER your mods are complete and the truck is a stable platform and back running and driving again; it wouldn't make any sense to log your stock motor and try to then create a tune for some other motor based on what your stock one is doing.