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Real World 8.1 Vortec Experience ( and other Motors )

BONER

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Who here has owned a Silvy or Sierra with the 8.1? IDGAF about MPG. Just looking for overall reviews.

Has anybody rebuilt one of these motors for more power? Are parts readily available? I would think a cam and set of heads would be worth 75-100hp?

Post up. Post pics too, if you got em. I don't mind looking at trucks. :)
 

mjc

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I have a 03 3500 with an 8.1. never had any problems in 100k. They do need some rpm to pull heavy loads. Never done anything but oil changes and 1 set of plugs.
 

pwerwagn

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I have an 05 5500 kodiak with one. I absolutely love it. Tows 30k lbs around fantastically, even up at ~11k ft. Mine has the Allison behind it with 4.88’s.

I usually get 7-8mpg, but I’m never less than ~23k lbs. Doesnt get any worse mileage than my cummins at the same weight.

There are some cheap mods you can do. Plugs, plug gap, t-stat, etc. To make much more power, the intake and heads are a huge limiting factor. The tq management built into them also requires correct use of the pedal. There are a few tuners out there that claim big power increases, but I think most of them are just removing a lot of the tq management.

There is a bunch of info in the 8.1 section on the GM forum.

In short, I have zero dislikes with mine. I’ve climbed hills with it spinning 4K+ rpm at wot for 20 minutes straight, and it just keep rollin along. I’d buy another in a heartbeat and I am not a GM Guy.

Jeff
 
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02HoWaRd26

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I’d imagine being it’s the same motor as the 496, that you could do any of the Raylar parts and gain headway. Also i do know on the 6.0 in AZ most will desmog the truck and get good gains, I’m sure same with the 8.1 as well.
 

RogerThat99

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I want to find an 8.1. I have a 2500HD with the 6.0l. It gets crappy mileage, so I might as well have the 8.1. LOL.

I don't mind the mileage mine gets, it just needs a larger tank for more range. I tow 89 miles one way to Discovery Bay. I usually have to stop nd full up somewhere on the the way back, or I am am on fumes when I get home.

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02HoWaRd26

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I want to find an 8.1. I have a 2500HD with the 6.0l. It gets crappy mileage, so I might as well have the 8.1. LOL.

I don't mind the mileage mine gets, it just needs a larger tank for more range. I tow 89 miles one way to Discovery Bay. I usually have to stop nd full up somewhere on the the way back, or I am am on fumes when I get home.

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I’ve got a buddy out here who had two 6.0 trucks that he seldom still used for work, he ended up taking one to CBM in Rancho and then immediately took the other up there. They retuned them and he said the run, drive, and pull better as well he gained quite a bit of fuel economy
 

BONER

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I was doing some searching yesterday and it actually looks like 8.1 parts are pretty expensive. Raylar Heads are $3500.

I rode in a 8.1 truck a long time ago. Truck had 150k on it. Felt like the motor was just wore out and tired. I have full intentions of going through the motor eventually, no matter what brand or size.

End goal is just to have a cool Family / Boat hauler.
 

pwerwagn

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I was doing some searching yesterday and it actually looks like 8.1 parts are pretty expensive. Raylar Heads are $3500.

I rode in a 8.1 truck a long time ago. Truck had 150k on it. Felt like the motor was just wore out and tired. I have full intentions of going through the motor eventually, no matter what brand or size.

End goal is just to have a cool Family / Boat hauler.
8.1 parts are $$$. That’s a fact.

Go poke around on the diesel place. Lots of 8.1 info.

Beyond the t stat, plug gap, tuner and cold air, it gets $$$$ quick.

Here’s a thread to start with. Tons and tons more info there and a bunch of other forums.

https://www.dieselplace.com/forum/6-other-vehicles/9-gm-gassers/295135-best-performance-upgrades-8-1l-496-a.html#/topics/295135
 

BONER

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BONER

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Any Triton V-10 knowledge in here? :)
 

thmterry

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My 2001 Suburban with an 8.1L is a great truck. Pulls strong, good power and has a 38 gallon gas tank because it needs it.
 

BONER

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My 2001 Suburban with an 8.1L is a great truck. Pulls strong, good power and has a 38 gallon gas tank because it needs it.
This is another reason I'm sniffing around 8.1's. Because Burbs are Bad To The Bone. So much room for activities! Stereo's, Guns, Targets, Buddies, Tools for the Money Pit it'll be towing, a cargo area that locks....
 

wishiknew

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I had a 2003 2500 that got 385000.00/before trade in never touch motor or trans or rear ended the rest of the truck was worn out one other thing it never passed a gas station 8 mpg at best
 

Yellowboat

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My dad had one for a long time, it ate cam sensors. Only prob he had.
 

Rbcconst

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I had one in a 2500 and a friend omg mine had one in a 2500. They burn a little bit of oil, maybe a quart between oil changes. Mine had 205k on it when I sold it. It was more fun to drive then the duramax. It was a beast. Mpg was definitely an issue. A little over 6mpg towing my trailer back from havasu with a slight head wind.


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Deja_Vu

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I would go with a 6.0. Cheap parts and plenty available.

I want to find an 8.1. I have a 2500HD with the 6.0l. It gets crappy mileage, so I might as well have the 8.1. LOL.

I don't mind the mileage mine gets, it just needs a larger tank for more range. I tow 89 miles one way to Discovery Bay. I usually have to stop nd full up somewhere on the the way back, or I am am on fumes when I get home.

Sent from my SM-G930V using Tapatalk
Do you have to smog test the truck?
A set of headers and a good flowing exhaust should get you more low end TQ and better economy.
 

RogerThat99

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I would go with a 6.0. Cheap parts and plenty available.



Do you have to smog test the truck?
A set of headers and a good flowing exhaust should get you more low end TQ and better economy.

I already have a 6.0L. Yes, I live in California...it has to be smogged.

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BONER

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Yup, I meant that for the OP, sorry.
Haven't bought yet. Was thinking about going with a newer 5.3 1/2 ton, but don't want to finance. So, looking at all kinds of options.

I've been shopping for 6+ months. I've also written Service a majority of my professional career even though other opinions vary, I know what trucks have a history of failure and which ones don't. At any rate, if I stick to my guns on a 8-12k budget I think I can get ALOT of truck for that little amount of money.
 

BONER

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Anybody ever build a motor for their Tow Rig? 5.3, 6.0, 8.1, 454 Vortec, Triton V-10???
 

Scapegoat

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There's a y pipe that helps the triton v10's I've had/have an excursion and f250 4x4 with good luck. Other than that getting a real tune done would be the ticket.
 
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