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.