Replacement exhaust manifold bolts

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Was cleaning the engine compartment of my escalade ext and saw that a couple of the stock bolt heads broke off the passenger side exh manifold. I'm gonna take it to a local shop to replace all the bolts (both sides) w new better bolts. I liked the arp bolts but there are a bunch of part numbers that says would fit with different underhead length (uhl). Do I need 20mm, 25mm or 30mm? Thanks
 
If room I would use studs and nuts. I've had much better luck. Whatever kind of threads into block with fine thread on the end. Use anti-seize on the head thread side.
 
Originally Posted By: Ihatetochangeoil
Whatever size you need, use 300 series stainless bolts/nuts/studs/washers and nickel antiseize. You will never again have a problem with rusted fasteners; in fact, I wonder why stainless exhaust fasteners aren't OEM?

Mine cost $20 and an afternoon to install.

http://www.milzymotorsports.com/stainless-steel-header-bolts-for-3x00-engines/


I'll never understand the infatuation with stainless hardware, Manifold bolts on LS engines are highly stressed fasteners especially on the larger 6.0L & 6.2L versions (higher exhaust heat), I don't use or recommend stainless in a stressed applications.
However.....If the OP has to have stainless, Use top of the line ARP hardware https://www.summitracing.com/parts/arp-434-1102 The rolled threads will help prevent galling & use anti-seize.

I would personally skip the Allen Heads also, I hate Allen drive bolts!
 
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Why are they highly stressed? What is stressing them?

BTW, nearly all fasteners are made with rolled threads.
 
Called a local shop, they recommended OEM replacement bolts over aftermarket (I said I wanted ARP). I don't think I'm going to use that shop.
 
Originally Posted By: barkingspider
Called a local shop, they recommended OEM replacement bolts over aftermarket (I said I wanted ARP). I don't think I'm going to use that shop.


They have probably been burned by people trying to go cheap. A lot of people don't want to spend the money for ARP, even when they are the obviously better choice. I sell the heck out of the OEM Ford exhaust manifold to head studs and nuts. Funny thing is there is a stainless upgrade on some applications and they usually sit and collect dust because customers don't want to pay the difference.
 
Originally Posted By: Trav
I know in the salt belt the SS studs are almost mandatory if you expect the repair to last but is rot an issue in socal?


Nope. I give the option just because it is there and I don't want to hear someone say they would have bought it if I had told them it existed.
 
I can understand that, the SS Ford studs in the TSB cured the rotten stud problem for good but as you say they were not cheap, I had one guy demand I use the studs from "Help" he provided because the SS were so expensive. Two years and the were rusted away again, then i was the worlds biggest MF for using them. LOL You cant win.
 
Originally Posted By: Kestas
Why are they highly stressed? What is stressing them?

BTW, nearly all fasteners are made with rolled threads.


The manifolds expand & contract so much that it bends the bolts back & forth 'til they break, They can also warp to the point the bolt heads pop off. If the bolt is broke off flush with the head......expandtion got it, If the head is popped off....Warpage is most likely. But as Trav said.....Check the manifolds for flatness. They also support the catalytic converters & y-pipe.

I could have worded the rolled threads comment a little better.....ARP does a better more consistent job at it.

This is a common issue on Texas trucks, It's not just because corrosion of the fastener.
 
Originally Posted By: Trav
I can understand that, the SS Ford studs in the TSB cured the rotten stud problem for good but as you say they were not cheap, I had one guy demand I use the studs from "Help" he provided because the SS were so expensive. Two years and the were rusted away again, then i was the worlds biggest MF for using them. LOL You cant win.


My saying at work about such things is "you can lead a horse to water, but sometimes you have to drown it to get it to drink." Thankfully I have been on vacation for almost 2 weeks so I have not had to worry about that. Except for the text and facebook messages from managers and wholesale customers wanting me back.
 
Went to another local shop, the mechanic says he sees this a lot, say it'll be $400 to remove the exh manifolds, remove the bolts that had broken off heads (4 ea), machine the manifold surface, replace gaskets, and install w new bolts. I told him to go ahead but then he says, for an additional $400, he will install shorty headers (he had the Gibson GP 500 at his shop). WTH, I pulled the trigger. I know LT headers are much better, but I'm in CA, and don't want to deal w smog issues. I hated that when I had LTs on my vette.
 
Way to go man. I think I would love headers on my 6.0 one day.

My bolts look like they have seen better days as well.


The cost seems cool- it was just the fact I didn't think it could be done that worried me- you know? Chasing broken bolts and rusted threads in tight quarters!!!




btw my truck is at about 171k and is an 03 model.
 
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