Header install help

bmp5484 · January 7, 2019

Got a set of JBA cat4ward shorties coming for my 2015 5.3 and am trying to get some better hardware to put them on with. My mechanic says ideally it would be 2 studs and the rest bolts for each side, but I don't see any kits like that and while cost isn't a concern, I'd rather not buy 2 kits/piece meal it, but certainly will if that's the best way forward. So it looks like Stage 8 and ARP are kinda the 2 choices, with Stage 8 looking better initially, but concerned if the locking tab will always have something to rest against? I'll post links to the 2 kits I'm eyeing, and any input or other suggestions would be greatly appreciated!

https://www.stage8.com/product/8917-gm-lt-series-header-bolt-kit/

https://arp-bolts.com/kits/ARPkit-detail.php?RecordID=4908

Also, if someone would please confirm that these are the correct kits for my truck (2015 Silverado 5.3)?

ARP site says "6.2 LT1 small block", and the Stage 8, "All LT series (LT1 thru LT4) 2014-on" but both come up as the listed kits for my make/model/year (10 x 8mm-1.25x25mm)

Thanks in advance!

drentlaw1 · January 7, 2019

I’m running stage 8 on mine. They came with my Kooks headers. Never had a issue with them coming loose or rattling.

EaglesZ71 · January 7, 2019

I also have the Stage 8 fasteners that came with my KOOKS Long tube headers and they work great no problem as of yet!

Both great quality products.

imiller1974 · January 7, 2019

1 hour ago, bmp5484 said:

Got a set of JBA cat4ward shorties coming for my 2015 5.3 and am trying to get some better hardware to put them on with. My mechanic says ideally it would be 2 studs and the rest bolts for each side, but I don't see any kits like that and while cost isn't a concern, I'd rather not buy 2 kits/piece meal it, but certainly will if that's the best way forward. So it looks like Stage 8 and ARP are kinda the 2 choices, with Stage 8 looking better initially, but concerned if the locking tab will always have something to rest against? I'll post links to the 2 kits I'm eyeing, and any input or other suggestions would be greatly appreciated!

https://www.stage8.com/product/8917-gm-lt-series-header-bolt-kit/

https://arp-bolts.com/kits/ARPkit-detail.php?RecordID=4908

Also, if someone would please confirm that these are the correct kits for my truck (2015 Silverado 5.3)?

ARP site says "6.2 LT1 small block", and the Stage 8, "All LT series (LT1 thru LT4) 2014-on" but both come up as the listed kits for my make/model/year (10 x 8mm-1.25x25mm)

Thanks in advance!

Well, let us know how it goes, and if you think it's added any power. What are your plans with the Y-pipe?

bmp5484 · January 7, 2019

23 minutes ago, imiller1974 said:

Well, let us know how it goes, and if you think it's added any power. What are your plans with the Y-pipe?

For now, going to just leave it alone. Going to be relocating where there's no emissions in the near future. When that happens I've already got a buyer for the shorties when they come off, and I'll be going with a set of LT's and a cat-less Y.

DenaliX14 · January 8, 2019

6 hours ago, bmp5484 said:

For now, going to just leave it alone. Going to be relocating where there's no emissions in the near future. When that happens I've already got a buyer for the shorties when they come off, and I'll be going with a set of LT's and a cat-less Y.

Two things,

I have used stock style bolts (new) for two sets of headers for my 2014 Sierra Denali 6.2L. Kooks 1 3/4" and currently TSP 1 7/8". I never had an issue with either set up using them with loctite on the threads. (https://www.gmpartsdirect.com)

Also, you should be able to go with Long tube if you want. I live in MA and we're super strict on OB2 systems. We have to pass smog every year. With the the TSP Long tube headers to 3" Y pipe I have these (https://www.summitracing.com/parts/wlk-81724) cats. They're HUGE so fast flowing and eats up emissions all day. I have Zero Codes with all 02 sensors active. With the Kooks Catted Y I had p0420, p0430 codes i had to clear every day.

I'll post a video tomorrow when It's light out of the set up.

Edited January 8, 2019 by DenaliX14

imiller1974 · January 8, 2019

I'd like to see some pics of your set up.

I'm trying to decide if I want to invest in an exhaust for my supercharged 5.3...

Edited January 8, 2019 by imiller1974

DenaliX14 · January 8, 2019

1 hour ago, imiller1974 said:

I'd like to see some pics of your set up.

I'm trying to decide if I want to invest in an exhaust for my supercharged 5.3...

Not that I like doing this but it's easier.

https://www.silveradosierra.com/ecotec3-6-2l-v8/sierra-denali-6-2l-with-simple-mods-t707461.html

bmp5484 · January 8, 2019

12 hours ago, DenaliX14 said:

I have used stock style bolts (new) for two sets of headers for my 2014 Sierra Denali 6.2L. Kooks 1 3/4" and currently TSP 1 7/8". I never had an issue with either set up using them with loctite on the threads. (https://www.gmpartsdirect.com)

Thanks for the input. I see on the gmpartsdirect site that the exhaust maniflold's are the same for the 5.3 & 6.2, so am I correct assuming that the hardware would be the same for the install on both? I'm finding all the ARP harware that comes up for my truck says, "SBC 6.2 LT1" on the packaging, but should be same/work fine for my l83?

Also, have you (or anyone reading for that matter) replaced the collector bolts when installing your headers? I see 3 different ARP part's depending on thickness of flange. The JBA website lists "3/8" machined flanges", so would that refer to the collector flange too?

DenaliX14 · January 8, 2019

5 minutes ago, bmp5484 said:

Thanks for the input. I see on the gmpartsdirect site that the exhaust maniflold's are the same for the 5.3 & 6.2, so am I correct assuming that the hardware would be the same for the install on both? I'm finding all the ARP harware that comes up for my truck says, "SBC 6.2 LT1" on the packaging, but should be same/work fine for my l83?

Also, have you (or anyone reading for that matter) replaced the collector bolts when installing your headers? I see 3 different ARP part's depending on thickness of flange. The JBA website lists "3/8" machined flanges", so would that refer to the collector flange too?

You’re correct they would be the same.

I have Not replaced the flange bolts since I went with long tube headers. I do have a subscription to Haynes.com. It currently says it is off-line however, as soon as I can login I will screenshot the instructions as well as the specs and the hardware and send it over to you

bmp5484 · January 8, 2019

25 minutes ago, DenaliX14 said:

I have Not replaced the flange bolts since I went with long tube headers. I do have a subscription to Haynes.com. It currently says it is off-line however, as soon as I can login I will screenshot the instructions as well as the specs and the hardware and send it over to you

Awesome! Appreciate it!

DenaliX14 · January 8, 2019

1 hour ago, bmp5484 said:

Awesome! Appreciate it!

DenaliX14 · January 8, 2019

1 hour ago, bmp5484 said:

Awesome! Appreciate it!

11 Install the heat shields, then install the bolts and gaskets onto the manifold. Retaining tabs surrounding the gasket bolt holes should hold the assembly together as the manifold is installed.

12 Starting at the fourth thread, apply a 1/4-inch wide band of medium-strength threadlocking compound to the threads of the bolts.

13 Place the manifold on the cylinder head and install the mounting bolts finger tight.

14 When tightening the mounting bolts, work from the center to the ends. Tighten the bolts in two steps to the torque listed in this Chapter’s Specifications . If required, bend the exposed end of the exhaust manifold gasket back against the cylinder head.

15 The remainder of installation is the reverse of removal.

16 Start the engine and check for exhaust leaks.

DenaliX14 · January 8, 2019

Specs

heatshield bolts. 89” inch lbs

Exhaust manifold bolts.

Origional cylinder heads = 17’ foot pound

new cylinder heads = 20’ foot pound

bmp5484 · January 8, 2019

1 hour ago, DenaliX14 said:

Thanks!

In the above picture it shows 6 bolts on the manifold and the correct bolt kits for my truck have 10 versus 12 for the one in the picture.

Did they just use that manifold for illustration?

I also noticed what looks like aftermarket/upgraded spark plug wires. I've heard that people have had to swap stock plug wires for MSD's to take care of fitment issues with headers. Wondering if I'll have any issues with just my set of shorties or if I should just go ahead and order a set. Don't have any problem putting them on if need be, but it wouldn't hurt my feelings to run the stock wires for a little longer than the current 28k miles lol