Repair-It

First time. This particular specimen was an 02 (first year) and, interestingly, a 2500 (3/4 ton). So it had the 8100 and 4L85-E trans. Very stout running gear.

Exterior
The 02 had the ugliest cladding of all the years. Here is a 2002.
https://en.wikipedia.org/wiki/Chevrolet ... lanche.jpg

The 03 looked better. Here is an 03-06:
https://en.wikipedia.org/wiki/Chevrolet ... he_WBH.jpg

Cool storage on each side of the bed.

Interior
Very comfortable cabin. Good rear seat room. This vehicle, despite being toward the end of its life (182k but rust issues), was nicely equipped. It had: auto climate control, heated seats, moonroof, trans temp gauge on the dash. But the coolest part is that you can remove the rear window, stow it, and lower the whole rear part of the cab to extend your load floor of the bed. I thought this was really cool. The window is defrosted and uses two metal contacts rather than wires (since the glass comes right out). No tools needed of course. Also no check engine light.

The drive
I liked it. It was all beat on the outside (and like never vacuumed, etc.) but in typical GMT-800 fashion, it drove great. Uber torque from the engine. The 8100 had 340 hp and 455 lb-ft. That is more power and a bit less torque than the Duramax, which was also available in 02. There is something to be said about a stout, reliable gas engine. You pay in fuel, but there are literally no other down sides. Plenty of power and torque. 12,000 lb tow rating which is exactly as good as a 3/4 ton truck (even with the Duramax). I think the long term maintenance/repair costs of the gas are FAR lower than a diesel. And diesel costs more than premium, yet this 8100 happily drinks 87 (with 9.1 compression, why wouldn't it?). Side note, here is a short list of expensive things you'd face on a Duramax with higher mileage:
- Head gaskets (HUGE job, bad enough on a gas engine, like 5x worse on a diesel and more likely to fail)
- Injectors (same - way harder to get to and way more expensive parts, and more likely to fail, especially the early ones)
- Fuel pressure regulator (same, AGAIN. hundreds of dollars, buried under shit, more likely to fail)
- Obviously there is a turbo that can fail or leak oil
- You get the idea

Plus the 8100 is not the Triton V10. So it has that going for it, as well.

It had hydroboost brakes which worked just fine. Steering felt like a 3/4 GMT-800, which is to stay, some play on center but very solid feeling with no wander at all. Surprisingly solid and direct. I was impressed at the ride actually. The damping was good, and the ride was comfortable and controlled. I was driving on some tight backroads and there was nothing unwieldy about it at all. I wanted to push it some but my passengers would have objected.

So yeah, it was cool. My father in law is thinking about getting a 1500. We'll see.

Production numbers by calendar year:
2001 52,955
2002 89,372
2003 93,482
2004 80,566
2005 63,186
2006 57,076
2007 55,550
2008 35,003
2009 16,432
2010 20,515
2011 20,088
2012 23,995
2013 16,986

They got rid of the 3/4 ton for the GMT-900 update in 2007. Which wears the SUV front end, which I think is quite handsome. 8100 went away but you could get the L76 6.0L with even more power (361 or something).

https://en.wikipedia.org/wiki/Chevrolet ... lanche.jpg

Quick fuel calcs.

87 my way is around $3.00/gal. 93 is like $3.45. And diesel is...oh. Only $3.20. Ok.

Well, that's not as bad as I thought. But it still means you are starting at a 6.7% deficit. Still, a diesel would easily 20-40% better fuel economy than an 8100, not that you could get a Duramax Avalanche anyway.

Has anyone ever put a turbo on that 8100? Seems like it might be a good combo.

I don't believe they are good candidates. They aren't nearly as overbuilt as the LS stuff.

I don't agree with some things here but interesting info anyway.

https://dustrunnersauto.com/vortec-8100/

You might be wondering, why isn’t this massive engine used in a performance application? The Chevy LS is super popular so why isn’t this engine? Well, there are quite a few things holding the Vortec 8100 back from ever becoming popular:

1. Iron block and heads, total engine weight is over 750 lbs.
2. Older big block parts don’t fit on the Vortec 8100.
3. Chevy LS parts don’t fit on the Vortec 8100.
4. Limited production makes them harder to find than an LS.

Vortec 8.1: Applications
Like I mentioned above, the Vortec 8100 was used in GM pickup trucks as a diesel alternative. But, it was also used in a few other applications:
Chevy Silverado/Sierra 2500HD & 3500HD
Chevy Suburban/Yukon XL 2500
Chevy Express 2500 & 3500
Chevy Avalanche 2500
Chevy Kodiak
Workhorse Class A motorhomes
T-98 Kombat armored vehicles
Malibu Boats
MasterCraft Boats

It will cost a large amount of money to build an 8100. It is also big and heavy.

I believe the HP peak is at 4200 rpm. That is hilarious.

Post from 2006:

8.1L vs 6.8L, there's no replacement for displacement

Not sure what the class rating was but it was a 34' gulfstreem with the ford v10, I've never heard a motor work so hard to move a vehicle down the road. We borrowed one and we drove it from Rhode Island to Daytona twice getting a total of 5mpg, but what do you expect when you're 3/4 throttle doing 65mph on level road. Any incline it would downshift twice and the speed would drop to 45 with the pedal to the floor.

The owner traded it in for one on a GM chassis. The GM vortec was a world of difference to drive, though we never got a chance to take it down the Daytona, I think the GM one was 36' as well. I was able to drive it for a short distance (about 250 miles) and was pretty impressed how it just chugged along, it feels like a torque monster compared to the v10. It also got 8mpg and that was heading north into the hills unlike the flat roads heading to Florida.

I don't know what the ford makes for power, but the 8.1L is 340hp with 450 ftlbs of torque stock.

I've heard rumors of a GM 7.4L V-10 being built to replace the 8.1 for 2007?

Yeah, take that Ford!

Oh no, only 320 hp in the Avalanche apparently. Still more than a period Duramax.

I saw a MT article where the 2500 8.1L Avalanche was actually slower than the 1500 with the 5.3L due to the extra weight. I guess it probably still tows better though.

It felt fairly sprightly to me, but who knows.

And yeah it is a lot heavier than a 1500. The extra weight manifests as better trailer control, but it also means for a given trailer weight, that is a smaller percentage increase in gross combined weight, so the heavier vehicle inherently slows down less. Which people have, over time, mistakenly associated with some kind of turbo diesel engine trait. Don't get me wrong, a diesel probably does have a pretty wide range of usable RPMs where the HP output is basically leveled off, whereas the gas engine would have to rev up towards redline, and that does help drivability. But I think it's just the weight thing that makes heavy trucks handle trailers better. By all accounts, the 8100 is a great towing platform whereas even with the 5.3L in the same truck, it would have to have like 4.56s to be effective. The Avalanche I drove had 3.73s I believe and it had usable power right off idle (with no lag I might add).

Look at these:
https://www.internationaltrucks.com/trucks/durastar

As little as 200hp and no more than 380. These are trucks that gross between 22,000 and 44,000 lbs, and can also tow another 22,000+ on top of that. How well do you think 200 hp motivates 66,000 lbs? Not well. But if you added a 8,000 lb trailer to one of these, you probably wouldn't feel much whereas it would be extremely noticeable on a 1/2 ton. It goes from balls slow to a little slower than balls slow. While the 1/2 ton would be miles faster empty AND towing, even though adding the trailer was a huge drag.

http://www.motortrend.com/cars/chevrole ... alanche-2/

Good comparison of the 5.3 and 8.1.