It's HG time in the near future. Any recommendations on parts.

chevymec

New member
Aug 8, 2020
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My '05 decided to try and hydro lock the other day after sitting for about 2 weeks. I've know the HG are bad for a while.. 7 years. I plan on studding, new return hoses, drivers manifold upgrade, FPR, glow plugs, another water pump, and the obvious new gaskets. Truck is stock other than a CAI and S&B mouthpiece. Don't plan on deleting but will be cleaning/checking the egr cooler, and I know there are 2 injectors that the balance rates are low 3's. other 6 are 1 and 2's Any other recommended pieces to replace while it's apart? Plan on starting to gather them here and there. 168k miles. Already have some GM sourcing problems through the dealer.

So far I have ordered
GM C gaskets
GM glow plugs
GM P/s pump... it's been a problem for a while
GM Surge tank and cap
GM HG kit
GM injector seals and o rings
GM down pipe clamps
GM Exhaust manifold hardware

Still to be ordered
ARP studs
Bosch return hoses
Water pump
PPE 3" down pipe
Banks 4" monster exhaust
BD drivers exhaust manifold
PPE firewall insulator (thanks to a mouse destroying it)
Bosch FPR


Not looking for a HP build but a good DD. I know the best way to keep it reliable is to keep it stock, but I hate to put something back in that can be replaced/upgraded and still be reliable on the stock fuel system. Not sure on getting a real tune afterwards or keep the Superchips. Are the PPE up pipes a good upgrade for what I'm trying to stay at or would it be a waste since my stock units are still good? Banks Boost tube?
 

2004LB7

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Dec 15, 2010
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I'd do an S&S or equivalent metal return T fittings over the Bosch plastic ones.

Use the newer plastic impeller water pump

Make sure you don't get the gold head gaskets
 

chevymec

New member
Aug 8, 2020
20
2
3
I'd do an S&S or equivalent metal return T fittings over the Bosch plastic ones.

Use the newer plastic impeller water pump

Make sure you don't get the gold head gaskets
When you say gold, you mean the AC Delco? These are genuine GM, well the one I have is. I'll check out the S&S pieces.
 

2004LB7

Well-known member
Dec 15, 2010
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When you say gold, you mean the AC Delco? These are genuine GM, well the one I have is. I'll check out the S&S pieces.
 

JSimmsy

New member
Mar 31, 2019
24
6
3
Ohio
I know I'm almost a month after this was first posted, but I did HG on my LBZ over the summer with 220k on the clock and here are my tips and advice.

Send your injectors to get cleaned. It's $50/injector at most places. I skipped this part and ended up buying new ones from Lincoln diesel. But I went 45 over as well. But if I was staying mostly stock, definitely get them cleaned and tested.

Be prepared for broken bolts on the turbo, up pipes, manifolds, and glow plugs.

I bought a top end and stud kit from pro source diesel. It had literally everything in it I needed. You don't need ARP head studs staying at your HP level. Save you some coin and look at your options.

I personally think it's a waste for the BD manifold. But doing quality manifolds and up pipes do help EGTs a lot and help get that deeper tone. But that's not cheap. You could gasket match your factory stuff while it's all apart...

You'll need more brake clean and liquid wrench/pb blaster than you think you'll need

I also agree about the metal injector fittings.

Get some silicone grease and anti seize for everything.
 

chevymec

New member
Aug 8, 2020
20
2
3
I know I'm almost a month after this was first posted, but I did HG on my LBZ over the summer with 220k on the clock and here are my tips and advice.

Send your injectors to get cleaned. It's $50/injector at most places. I skipped this part and ended up buying new ones from Lincoln diesel. But I went 45 over as well. But if I was staying mostly stock, definitely get them cleaned and tested.

Be prepared for broken bolts on the turbo, up pipes, manifolds, and glow plugs.

I bought a top end and stud kit from pro source diesel. It had literally everything in it I needed. You don't need ARP head studs staying at your HP level. Save you some coin and look at your options.

I personally think it's a waste for the BD manifold. But doing quality manifolds and up pipes do help EGTs a lot and help get that deeper tone. But that's not cheap. You could gasket match your factory stuff while it's all apart...

You'll need more brake clean and liquid wrench/pb blaster than you think you'll need

I also agree about the metal injector fittings.

Get some silicone grease and anti seize for everything.
Thanks. Already have all new manifold and up pipe bolts. I looked and the PPE manifold and up pipes but read on one of the sites it was mixed reviews. I liked the BD manifold as it already had the boss for an EGT. I will stud it even if I plan to stay at this HP level. Right now it is hydolocked. I had been able to keep bumping it over till it would start. Pretty sure I just added a starter to the parts list. I knew better but I rolled the dice. I will be pulling the wheel wells out and pulling the glow plugs and free it up.
 

Harshman

Member
Apr 20, 2021
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8
harshmanauto.com
When you get the heads off check all the piston heights to make sure you didn't bend a rod from the hydro lock. Also sounds like you may have had coolant in the cylinders for long periods of time. Could have some rusty or etched cylinder walls.
 

JSimmsy

New member
Mar 31, 2019
24
6
3
Ohio
Thanks. Already have all new manifold and up pipe bolts. I looked and the PPE manifold and up pipes but read on one of the sites it was mixed reviews. I liked the BD manifold as it already had the boss for an EGT. I will stud it even if I plan to stay at this HP level. Right now it is hydolocked. I had been able to keep bumping it over till it would start. Pretty sure I just added a starter to the parts list. I knew better but I rolled the dice. I will be pulling the wheel wells out and pulling the glow plugs and free it up.
I just meant you didn't need to pony up for the ARP studs. There are other brands of studs out there that will work just fine for a few hundred dollars less.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,330
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83
Central OH
Just run new head bolts. Those xotic studs are enticing but IIRC Brad had some pop after sitting overnight on an engine in the shop?
 
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Dmaxwill

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Jan 18, 2020
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Just run new head bolts. Those xotic studs are enticing but IIRC Brad had some pop after sitting overnight on an engine in the shop?
The xotic studs that failed were equivalent to arp 625s strength, i dont think their lower strength studs have been a problem
 

JoshH

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ARP studs are proven to work, and thousands upon thousands of trucks have shown stock head bolts to be adequate for most people as well. Those are the only two options I would consider. I wouldn't risk a failure due to an unproven part for a few hundred dollars because my time is worth more to me than the money saved if I have to go back and do it again because a more budget friendly part isn't up to the task.
 

chevymec

New member
Aug 8, 2020
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Well my HG leak is definitely on Cylinder 2. Runs fine other than that. Starter sounded worse than it was. I didn't pull glow plugs 6 or 8 but #2 was soaked and all the others were dry. I gutted the radiator cap so no pressure will build up. It just pushes the coolant out. Truck has to make it through the end of the year before I can tear it down. On top of this, #7 injector harness wire is having the rub problem at the FICM. I really love/hate this truck....
 

Bdsankey

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I've had issues with Xotic's XP2 line of fasteners (625 equivalent) as well as issues with their Cummins studs not holding worth a damn. Because of that I've stopped recommending/using them.

We stick to Gator and ARP for studs now as well as OEM bolts as they're quite proven as Josh stated. Gator and ARP use the same stud blanks, the difference is Gator finish broaches the hex and rolls threads overseas whereas ARP performs that operation in the USA.
 

1FastBrick

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Dec 1, 2016
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I've had issues with Xotic's XP2 line of fasteners (625 equivalent) as well as issues with their Cummins studs not holding worth a damn. Because of that I've stopped recommending/using them.

We stick to Gator and ARP for studs now as well as OEM bolts as they're quite proven as Josh stated. Gator and ARP use the same stud blanks, the difference is Gator finish broaches the hex and rolls threads overseas whereas ARP performs that operation in the USA.

What about the heat treatment, more specifically on the gator stuff?
 

Bdsankey

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What about the heat treatment, more specifically on the gator stuff?
From what I've been told the products are heat treated in the same facility since threads are typically rolled post heat treat.

The blanks may already come with the hex broached before final processing/thread rolling, even then that specific feature (hex for installation/removal of the stud) doesn't require the same heat treated surface the rest of the fastener does meaning that if the surface hardness of the inside of the hex feature is lower it isn't an issue.
 
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1FastBrick

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From what I've been told the products are heat treated in the same facility since threads are typically rolled post heat treat.

The blanks may already come with the hex broached before final processing/thread rolling, even then that specific feature (hex for installation/removal of the stud) doesn't require the same heat treated surface the rest of the fastener does meaning that if the surface hardness of the inside of the hex feature is lower it isn't an issue.
Cool, I was just Curious if they were doing it overseas since they were rolling the threads over their. As long as they are testing the batches here and verifying quality, shouldn't be an issue.
 

Bdsankey

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Cool, I was just Curious if they were doing it overseas since they were rolling the threads over their. As long as they are testing the batches here and verifying quality, shouldn't be an issue.
They seem to be. I've used quite a few of their normal strength stuff without any issues and I've used half a dozen or so of their competition series (625 equivalent) and had zero failures to date. Their packaging is far superior to anything ARP sends out. Gator sends a bottle of Amsoil assembly lube as their preferred lube which seems to be fine.
 
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1FastBrick

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They seem to be. I've used quite a few of their normal strength stuff without any issues and I've used half a dozen or so of their competition series (625 equivalent) and had zero failures to date. Their packaging is far superior to anything ARP sends out. Gator sends a bottle of Amsoil assembly lube as their preferred lube which seems to be fine.
That's interesting to know on the lube.

I have heard from a few people the ARP lube does not break down in oil and they prefer to use CMD Lube #3 instead. I know a few rod manufactures supply it with their rods using ARP bolts.