Suburban 2500, 6.0....Exhaust manifold bolt repair worth the effort?

c good

Original poster
Member
Dec 8, 2011
531
Just noticed I have three bolts broken off on the exhaust manifolds. The driver's side most forward bolt, and most rearward bolt. Both broken off, not fallen out. The front bolt is broken off flush with the head, the rear bolt is broken off flush with the manifold.

The passenger side is most rearward, broken off at the manifold. So, this involves at least one e-z out type of repair...luckilly the most forward bolt on the driver's side....

The vehicle is not storing any emission codes....there is a very slight....to the trained ear...exhaust leak. There is no evidence of exhaust leaking at these points....soot, carbon, etc...so any potential erosion of the heads seems minimal.

The vehicle has 177 K miles on it. In otherwise excellent condition....I'm just thinking of running it until it throws a code or the engine needs to be rebuilt or replaced....

What are your thoughts on this? Thanks....c good
 

Reprise

Lifetime VIP Donor
Supporting Donor
Member
Jul 22, 2015
2,724
If the leaks are that undetectable now and not causing issues / codes, as you mentioned, I'd leave as-is, myself.

Or, you might try these - if the leaks get worse.
https://www.amazon.com/dp/B00GHT9L4O/?tag=gmtnation-20
@MRRSM did a write up on them a little while back, I believe.

They're made by our 'favorite' aftermarket vendor (Dorman), but there's no moving parts to these, so a better than average chance of them actually working (short-term *and* long-term).

If I hear more good things about them, I'll use them on mine for sure, when the time comes. It is not an easy matter to extract broken manifold bolts, IMO - especially in-car.
 

c good

Original poster
Member
Dec 8, 2011
531
Thank you Reprise for the info. I'm fairly mechanically inclined....but I have no clue as to how this clamp might work. Is there a link to a video that might add some clarity? I will try my Google search and let you know if I find anything...Thanks...c good
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
I would actually take the heads down and remove the broken bolts and get them replaced. It may seem like a lot of work but I think you may save yourself issues later.
 

Blackwater

Member
Aug 14, 2015
477
Lawton, OK
I would put some trick flow heads in, headers and a cam. Call it a day.
 
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m.mcmillen

Member
Apr 29, 2016
554
Wisconsin
I would replace the bolts and the gasket. I just worked on a 6.0 that someone had used the Dorman clamps for several years. The exhaust manifold gasket was bad so I pulled it all off and removed the broken bolts. Two of the bolts were pretty easy to get out, despite being in Wisconsin, I was able to use vice grips to back them out. One of the bolts was broken off flush with the head. I was able to weld a nut to the stud and get it out pretty easily.

The bad part is that when I went to put the manifold back on, the bolt holes would not line up. I'm thinking that not having the bolts in place allowed the manifold to warp. I had to buy another exhaust manifold.
 

Blackwater

Member
Aug 14, 2015
477
Lawton, OK
Trickflow Heads (TFS-3061T001-C02), Matching Trickflow cam (TFS-30602003) (228 int/230 ext dur @.050, .585 int/ .585 ext lift @ .050, 112 LSA). The recommended compression is 10.5 for this cam profile but it will give you considerable amount of power. If you plan on forced induction then the LQ4's dished pistons with 9.4:1 compression would be just about right and will work great with this Cam. You can also get LQ9's flat top pistons has 10.1:1 from factory and get thinner head gasket which would put you around 10.3:1 which can get close. You can also get some Male domed pistons to get that compression ratio. No more than 11.5:1 otherwise you would have to use a higher grade of fuel to keep denotation down. Denotation kills engines. That's why they were 7.5 and up to 8.5:1 before advanced timing came to engines. Now if you use stock bottom with the new heads and cam you can net 480hp from 300hp @ 4400 rpm with a good tune. With the 10.1:1 compression you can net 500 to 525Hp. With the 10.5 to 11.1 you can get 550to 580Hp.

Another way, you can go further and stroke the engine. With a 4 in. bore and 4 in. stroke will bring the displacement from 364 CID 6.0L to 402 CID 6.58L. You can also use the same stroke and bore the engine to .030 which will give you 408 CID 6.68L. With the other components I mentioned will defiantly make well over 600+ Hp naturally aspirated.

If you want a more muscle car meaner sound you can shorten the LSA to 110 or 108 and create a nice lope.

I hope this helps you. I'm a big fan of V8's, there transmissions and differentals.
 
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