19AT4

Get a kit that comes with new upper control arms (Upper ball joints are pressed in them from factory, but you can replace them on the aftermarket ones) check out ready lift. They have the proper kits

They also make a kit that's strictly for the AT4 models (#1318). I see that ready lift doesn't sell the spacers anymore without the upgraded control arms, probably because of all the failures. You'd think a 1" would be safe but it's hard to say. I even jacked my truck up a month ago to check the ball joints and I couldn't find any play.

The 2” rough country, the dealer wanted to install a different level that goes under the strut but they wouldn’t warranty it either. I called rough country and they weren’t any help, I even contacted them before I bought the kit asking if it would hurt the geometry and they said no. All the levels are the same, they just go in different spots. Unless you fix it with the new UCA’s that correct the binding.

For all you guys in here with levels without new UCA’s. I’d be careful, 10,000km later (6000miles) the front end took a beating. The ball joint completely separated, dropped the UCA on my tire and wrecked the CV axle. The left side needed a ball joint replacement as well. $2500 later it’s fixed and back at factory height. Looks like a car again (Use to have 34” Toyo MT’s with the level). Time for some 275 or 285/65 Ridge grapplers and I’m calling it a day unfortunately.

Plus I put the truck on a jack and tested to see how the ball joints were. I was a bit worried from other horror stories I read. There was zero play.

I don’t think they torqued the bolts properly when they had it all apart. I called rough country about it and they said there’s no way it should have came apart like it did. Especially considering all of the trucks miles are highway. I’m not sure what all’s different between the AT4 and non AT4 models but I know they got the extra 2” from longer struts. The angles all looked fine with the 2” level.

There must be more than the eye can see, the CV angles were great with this level. That was one of my worries when I got the kit back in Jan.

2” rough county, I called them about the failure. They said there’s no way their kit could have caused that, especially because my truck only sees highway driving. They blamed the shop that installed it. GM got back to me this morning with a bill of $1800 to get it all fixed. They said it was caused from the added stress but the mechanic said to use leveling kits that put spacers below the struts. He said you’ll be perfectly fine with that.

It’s at the dealer, waiting to see what all needs to be replaced. I see that motofab offers a 1” level that doesn’t require the strut to be pulled apart for the spacer. I hate the factory rake. Plus I had 35x11.5’s on order which I had to cancel.

Well I thought it wouldn’t happen to me, but my ball joint failed, collapsed the UCA and pulled my CV shaft out while on the highway. I highly recommend upgrading to new UCA’s with any levelling kit. I only had 12,000km’s with it installed. I would have bought them but the new UCA’s stick out further in which you can’t run the stock wheels without spacers if you get bigger tires. I have no interest in running spacers. Some food for thought...

It's probably 4-5 tenths quicker in the 1/4 over the previous 5.3's. The 6.2 is obviously quicker in every way but the race isn't a blowout like I expected.

True, they're significantly quicker than the last gen 6 speeds. I also wonder how the power curve is comparing the 5.3's and 6.2.

Yep it didn't make any sense to me, I know they'd both do much better at sea level. In the cab I could hardly notice a difference in power, he previously had a 8 speed 6.2 and he said the new one is a dog compared to his last one. I hear the 8 speeds were quicker in the 1/4 mile. I've yet to find any videos of the new 6.2 in the 13.9 range stock.

He was on 32" street 6 ply tires and I was on 33.3" 10 ply's so I think the wheel and tire weights were very close, plus I think the AT4's weigh a little more than the denali's? Mine was 2" taller than his If that counts for anything plus I had a 170lb passenger. I raced my previous truck down the 1/4 with 33's and 35's and there was 3/10th's difference.

Those are really impressive times! His was around 7 seconds, I know the density altitude up here is brutal but my 5.3 does it in 7.2 seconds. It doesn’t make much sense to me, he should have destroyed me. We tried launching it like you said and by brake torquing it. There’s a lot of torque management on these GM’s it seems like.

I've always been curious and I couldn't find any videos with a new gen 5.3 up against a 6.2. I was a bit surprised to be honest, here's the results.... the density altitude was around 5000ft above sea level, the trucks would probably lose 0.5 sec in the 1/4 at sea level. 19 5.3 with the 8 speed, 3.23 gears, 2" level on 22x10's, muffler/res delete 19 6.2 with the 10 speed, 3.23 gears, 2" level on 24x10's, Borla ATAK exhaust with a roto fab intake Draggy GPS performance tester, for anyone that doesn't know they're accurate to within 0.1 sec in the 1/4 mile (Proven) It shows you all the acceleration times, density altitude, slope (-/+1% range, the run becomes invalid if you're out of the range ect. 5.3, 15.2@91mph 6.2, 14.8@94mph 0-100mph runs the 6.2 was ahead by around 4 truck lengths, after 60mph or so the 5.3 can almost hang with the 6.2. The 6.2 gets the jump because the first few gears are pretty short. We did multiple runs with different launch techniques, they both had 2.2-2.3 60' times. I thought the 6.2 was going to absolutely destroy the 5.3's. I'd bet if the 5.3 was tuned it would be side by side with the 6.2.

With the DPF in place the sound won't change one little bit, it's just for looks.

I find that very hard to believe, plus you couldn't pay me to run their stuff.

From what I've seen it's tough to get lots of sound out of these new trucks, I swapped a Carven TR series in (Moderate sound level muffler) and it was extremely quiet. I taped over the rear mesh screens and it helped quite a bit, there's 3 mesh screens at the end of each tail pipe. My guess is that it just disperses the exhaust in sections to help quiet it down since there's no restriction within the pipes. But it drones bad from 100-110km. A friend of mine (Same truck, 5.3 with the 8 speed) put the carven R series in (Race muffler) and it sounds 100x better than mine but it drones terrible as well. Magnaflow is definitely on the quiet side but it's worth trying to see if you like it. It'll give you a low tone/rumble, especially if you leave the rear mesh screens alone. If you have the $ look into corsa. I've ran every muffler under the sun on my gas trucks and its the only muffler that has ZERO drone, it sounds completely stock on the highway. But just as loud if not louder than any race muffler from the outside, there's a lot of design and technology in that muffler. For the flappers I'd get them cut out, you can pin them open if you want but I don't think they have much effect on the sound level. If you do a muffler swap and leave the mesh screens alone along with the flapper it'll sound 100% stock in cab.

The mesh screens hold a TON of sound back, I had a Carven TR muffler swapped in and it made next to no difference. I blocked the screens off and it helped quite a bit but still tame. If you want any actual sound out of these you need a "race" muffler. The only cat-back that has any snap is the Borla ATAK and they won't make one for the 19/20 5.3's because they couldn't get the sound they wanted. I ordered the Flowmaster American thunder series cat-back with the quad black tips for $1000 (Borla is better quality but $2000 is outrageous), I'll be swapping out the super 40 for the 10 series!

I just ordered the RC 2" level for mine due to the fact I want to keep the stock 18's I have. I've seen a 285/75 done (35x11.3) with the new ready lift upper control arms but its too close for my liking. But you've got 20x9's from factory where the 18's are 8.5" wide I believe. That must be the difference, if you want to play it safe I'd use 275/65's with the ready lift upper control arms or a 35' with a RC 2" level.

HP tuners is the only option as of now. But like the rams; edge and diablo sport offered a tuner that piggybacked the PCM. It was less than half the price of buying the unlocked PCM and then purchasing tunes on top of that. The same thing just happened to the new duramax L5P. It's currently 7-8k CAD to delete them but edge just released the pulsar which piggybacks the PCM, an 80 or 90hp gain supposedly. I ran the pulsar on my ram and it worked real good! I think it'll come out for these 5.3/6.2's eventually.

To get any real sound out of these trucks you need a race muffler with the rear mesh screens blocked off. I did a muffler swap with the Carven TR series and it made no difference in the cab until I blocked those screens off. And even at that it's very mild, not much of a fun factor. I'll be trying the Carven R series next or super 10 series.

Yep of course, but all the 6.2 AT4's were about 6-8k more because they were completely loaded up when I bought my 5.3. I'm coming from a 2017 ram 5.7 8 speed with the 3.92 gears. This truck is only a few tenth's slower 0-60 than my ram was but the GM's weigh 5-600lbs less which helps a lot. I think the 10 speeds will be even better, I also bought my 5.3 knowing there was lots of aftermarket support but I had no clue they changed the engine up.... I'm hoping there will be tuning out fairly soon.