Jacob VH

So I have an 05 Sierra 2500HD 6L 4l80e
I also have another 04 LQ4 and 4l80e combo that I am going to build/refresh into an LQ9 for the truck and then swap in - so it should have ls2 rods. I already know sorta what I'm doing with the trans but I need help for the motor combo
So Far I know that I am definitely going to be putting a ported TB SS Intake and larger 4-bolt throttle body, Stock LQ4 AL heads that I will Port, mill to clean up, and CC, More than likely LQ9 flat top pistons to boost Static Comp to 10:1, Long Tube Headers, Cold Air intake, and then general rebuild items like balance, bearings, lifters, bore and hone, ex
The truck is 4:10 rear gear I'll likely be running 33s or 35s which should be pretty good in terms of daily driveability and RPM. Also being an HD the stock converter is about a 2200RPM Stall

I was looking at going with the Truck Norris cam but I'm now sorta looking at the TSP Truck Cam Stage 3 High lift. I know there are a bunch of other good cams for what I want as well, like the SUM 8719R1 or 8720R1 - Although the 8720 might be a bit too much cam. And do I need to do the trunnion upgrade and if so which one or are they all sorta unreliable?

And what is it that I want? Well, I'm looking for something I could daily drive and occasionally tow happily with the stock Converter Stall - So without losing much if any low RPM torque and gaining some top-end power. I'll rev the thing to 7500RPM if need be as I'm going to balance it but I doubt a torque cam will keep going past 7K. As for what I tow? For example, I'll be towing a 4500lb van on a small float with a full 200L drum of diesel in the bed this weekend. But that's probably the most I'd tow. I'm looking for something I could keep happily on 87 which shouldn't be too bad with a larger cam lowering the DCR. Plus shell stations where I live sell 88 as 87 which is a plus.

So alongside Cam I've heard quite a few people with smaller cams say they ran out of Exhaust flow or Injectors when dyno tunning so I'd need advice on that as well. Currently, post Cats I have a 3" y pipe into an Areoturbine 3030XL into a 3.5" tailpipe section. When I weld the exhaust after putting in Headers I'll probably ditch the Cats but in the end it will probably still be y pipe to single tailpipe of whatever size.

So any advice on Cam, Injectors, and What size exhaust I should be running would be awesome. And anything else I might have to do for a solid reliable setup

Thanks, Jacob VH

G Atsma

By putting a set of 243/799 heads on an LQ4 you end up with 10:1 compression AND a better combustion chamber desingn, plus the good ports they share with the 317 heads, which have a less desirable chamber design.
Just my .02.....

LilJayV10

iTrader: (39)

You aren't going to rev that intake out to 7500 and with those cams. I mean you can, but you will be probably 1000rpm past peak power.

Kawabuggy

iTrader: (1)

35's with 4.10 gears, and a 4L80E is going to be a DOG on acceleration from a stop. And you want to potentially run a stock stall converter? That thing is going to be like riding a city bus on take off... Lots of noise-very little movement. Run the truck Norris cam and expect to keep the RPM's under 6K for best torque production. If you decide to run the 35's, install at least 4.56 gears.. Injectors? Flex fuel injectors from the 2010 and later 5.3's seem to work well. Injector data is widely available so no guess work there. Exhaust? I run LT's into a 3" ORY, then into a 3" X pipe, then into true 3" duals into single chamber Flow Masters with turn downs.. It flows really well.. But it's also really loud. Exhaust is too personal a thing for anyone to tell you what YOU should be doing.

Jacob VH

well, I know that, just saying I'm happy to rev it out as far as needed

Jacob VH

ya, I know it will be a dog, I got 33s now. I just don't want to go huge on the converter. I'll probably stick with 4:10 and 33s for a while. a tuned motor with intake, porting and comp should make 30 ft lbs more at the wheels which will help, cam will hit around 3k and all will be good. don't need to win the race from the lights, just good power when passing ex
how many lbs are the flex fuel injectors? I hear the gen 3 computer has issues over 60lbs

gagliano7

I have the 6.2 flex fuel injectors and they are 50lbs which is plenty for your application. I am using them on a gen 3 5.3 and they were simple to tune and all the injector data is easy to find. The 5.3 flex fuel injectors are i think 36 lbs which will also be plenty for you.

Jacob VH

Thanks, Sounds like the 5.3 flex fuel injectors should be pretty much exactly what I need if I'm hoping for around 450 - 500hp at the crank with torque in the upper 400s as well. I didn't even think about it but trailblazer ss injectors are apparently 34 so assuming I'm more mid-400s rather than closer to 500 they will probably work pretty well.

99 Black Bird T/A

iTrader: (4)

I'd add,
New quality timing chain
New quality lifters & trays
New intake manifold gaskets if the old ones look squashed flat or are hard. After 15+ years they probably have seen their beat days.

Kawabuggy

iTrader: (1)

Your 4.10 gears with 33's means you are UNDER GEARED right now... If it were my truck.. I'd go RIGHT NOW to 4.56's, and at least a 3000 stall torque converter, and 706/862 heads, and flat top pistons.. That's a recipe for putting a smile on your face. Mix that with a CHEAP sloppy stage 2 cam, or even better (more $$$) the Chuck Norris-OR the new BTR Hot Rod cam... and I promise you that will be an awesome update to your truck. The trunion upgrade is a good choice.. Go with that as a recipe and I promise you it will put a HUGE smile on your face. It will wake your truck up like you would not believe is possible. You did not mention if your truck is 2 wheel drive, or 4x4.. Regardless, it's a HEAVY truck.. and you plan on putting bigger wheels and tires on it... you need to select a cam that is more TORQUE based at lower RPM's and NOT a high RPM screamer.. What I outlined above will make a very responsive engine combination. The SS2 would be the LAST choice in that scenario.. But if you want the truck to sound like it has a seriously bad attitude.. it will give you that.

Jacob VH

Ya, I was going to get new lifters, hardened push rods, and probably a double or ls2 timing chain. That's more along the engine rebuild/refresh stuff. I understand at .600 lift there will be a lot of stress on the complete valvetrain and if I'm spending money to make it faster, I'm gonna spend money to get it done right. I try to have that attitude with stuff I want to Keep

Jacob VH

Very true, It would be a fun combo (probably get me in trouble )
under geared is fine with me ATM. Can always throw a 4.56 in later when I do tires and the 4.10 already revs out while doing 130km/h on the highway (75mph ish) - probably just feels that way considering my last vehicle was a 4l60e with a 3.32 or something.
Torque Converter is definitely something I'm probably going to do but it's also something I can do later once I get everything else finished. And then I can also use the dyno sheet to choose a stall that's a little tighter than 3k for daily driving and towing, not that there is a huge difference between 2600 , 2800 ,and 3000.
I'm not a huge fan of a choppy cam idle so I'd skip on the SS2
In all honesty, it's between the TSP Stage 2 or 3 High lift and the Truck Norris. Heads I'm really looking at the 243s and I think I can source some cheap enough. Then I'll stick with dished pistons and still get about 10:1 comp
At the end of the day if I wanted something fast I'd buy some cheaper RWD GM car and throw the whole combo in that, gear it to do 80 (50mph ish) top of first with a high stall. But it's a heavy truck that I'm probably gonna daily for a while so... I'll throw some power at it but I don't expect it or need it to jump from a dead stop. the 4l80 has such a long first gear and the LS motors just love to rev, also it's 4x4 not that that really changes anything.

What do people generally recommend for trunnion upgrades? I've heard the heavy-duty C clips can still fail and let roller bearings get in the motor, and the brass bushing ones don't really last long either. What is really the best course of action?

Kawabuggy

iTrader: (1)

I've had good success buying the rockers from Summit with the trunion upgrade already installed. Takes "installer error" out of the equation, and they come ready to drop in after a little oiling/greasing.