Silverado exhaust manifold

[Chevy454z71]

2004 Chevrolet Silverado 1500 4wd 5.3 305000 miles

Recently blew out the exhaust manifold gasket on passenger side really bad and driver side slightly pulling a very heavy trailer over 800 miles, three bolt heads have been rusted off for a very long time but hasn’t leaked until now. I plan on getting gm manifolds/gaskets and dipstick tube. What do you guys suggest for hardware? Dorman sells there regular grade bolts and studs for it but also have a stainless steel option, from the pictures the manifold bolts are a1-70 and the nuts for the exhaust pipe connection are a2-70 but don’t know about the studs. Is stainless a bad idea and just go with the regular bolts? ARP studs or bolts? Anyone with long term use of stainless did the threads ever gal?

 

[Trav]

Use the stainless, when the old Ford 5.4 2V had trouble Ford issued SS for replacements, just use a little nickel anti seize on them.
Depending on the size you may be able to get copper plated nuts for it.

 

[atikovi]

Have you done this before? Even most shops stay away from these jobs as they can turn ugly real fast. At least get one of the broken bolt removal kits like,

https://promaxxtool.com/products/mikey

 

[BrendanC]

search for stainless studs. did my truck years ago and have done many since.

 

[Trav]

This is an easy template to make but there are cheaper ones.

https://www.amazon.com/Lisle-71400-Manifold-Drill-Template/dp/B07D4YMMFY

Have you done this before? Even most shops stay away from these jobs as they can turn ugly real fast. At least get one of the broken bolt removal kits like,

https://promaxxtool.com/products/mikey

I don't know what kind of shops you visit but if they are scared of this type of job they suck. Broken bolts and rusted studs are all part of a normal day.

 

[clinebarger]

ARP 8740 Chromoly 134-1120 with Loctite is what I use & yet to have a comeback, ARP 434-1102 Stainless is also a fine choice.

Welding a washer then a nut to the broken bolts is the easiest way I've found.

 

[Chevy454z71]

ARP 8740 Chromoly 134-1120 with Loctite is what I use & yet to have a comeback, ARP 434-1102 Stainless is also a fine choice.

Welding a washer then a nut to the broken bolts is the easiest way I've found.

What hardware do you use for the flange where the system attaches to the manifold?

 

[Snagglefoot]

For those who only have a small leak and only the end bolts heads are missing on the manifold you might be able to poor-boy it and run a bead of Permatex Ultra Copper where the manifold was leaking against the block. The bead will last thousands of miles if the metal was clean, and in my case the first bead deteriorated but the re-applied bead is still good, thousands of miles later. Ultra Copper is good for 700 F. There is no Copper it it, it’s just the choice of color Permatex used.

Edit: I checked my posts and found I’ve had this bead of Ultra Copper for 5 years.

 

[Rhymingmechanic]

Several companies also sell manifold clamps that might help when extraction/replacement isn't possible.
I had one or two missing bolt heads on the left front but didn't notice any leaks. The Dorman piece has worked fine for years.

https://www.dormanhdsolutions.com/p-19348-917-142.aspx

https://www.dormanproducts.com/p-66009-917-107.aspx

 

[ls1mike]

Several companies also sell manifold clamps that might help when extraction/replacement isn't possible.
I had one or two missing bolt heads on the left front but didn't notice any leaks. The Dorman piece has worked fine for years.

https://www.dormanhdsolutions.com/p-19348-917-142.aspx

https://www.dormanproducts.com/p-66009-917-107.aspx

I have used these and they worked awesome for years. I now just swap the fasteners out with ARP fasteners as soon as I get an LS/LT based vehicle.

 

[Rhymingmechanic]

I should say that Mike tipped me off to the clamps ^^

 

[someonesomewhere]

No personal experience with this issue, but I would not hesitate to use the ARP hardware recommended by clinebarger. He's a very knowledgeable guy, and ARP makes industry-leading hardware. Have used their stuff in many applications and had great results and 0 issues.

 

[someonesomewhere]

I have used these and they worked awesome for years. I now just swap the fasteners out with ARP fasteners as soon as I get an LS/LT based vehicle.

This sounds like a great plan of action. Address the issue before it becomes an issue.

 

[ls1mike]

I should say that Mike tipped me off to the clamps ^^

How long ago was that? I will be 50 this year and I don't remember things like I used to. LOL

 

[Rhymingmechanic]

How long ago was that? I will be 50 this year and I don't remember things like I used to. LOL

2017 according to my maintenance log. That's the only reason I know the date.

I do remember seeing your post in a broken exhaust bolt discussion. I think that made me go look at my truck and find 1-2 missing heads.