2002 Chevy 2500Hd with 8.1 & Allison, best setup so far
 

I just bought a new used 2002 chevy with 8.1 and allison, wow am i ever happy. Yes the duramax has more torque, but the 8.1 is more gearhead friendly. This truck pulls like a horse. I will never go back to a 4L80E trans again.
I heard they only used the 8.1 for 4 years, others say 2 years for the 496Ho in a truck. can any one tell me how many years they used the 8.1. Thanks
:whistle:

B38

I have the same truck. 2002 Gmc 2500 hd crewcab 8.1 I love My truck. It loves gas. But it will pull anything. Artie

I believe 2007 was the last year for the 8.1L in the Chevrolet HD's. I have a 2001 that I bought new with the ZF 6-speed. Great truck, pulls everything I have and still gets 15-mpg on the highway with no load.

I had a 01 Crew long bed w the 8.1. Great truck. Put over 100k on it in about 5 yrs.
NO problems what so ever. Used 1qt of oil per 1500 miles always.
Got 10 miles per gal ALWAYS!! 8 towing the 29 outlaw I had at time.
Had larger tires on so maybe speedo off a little.
You go 250 miles you put in 25 gal. ALWAYS

Picked up a 02 3500 Express van w the 8.1 for fleet. LOTS of power.

I think Chevy Avalanche had the 8.1 in the 3/4 tons from 02 thru 06. I have a 2005 3/4 ton Avalanche with the 8.1 and it has a lot of power and yes it likes to drink gas. I try to stay around 2k Avalanche when taking off to try and get better gas milage but we didn't buy it for it's gas milage.

I bought one in 01, and it was a horse.... Same setup 8.1 and allison, non 4x4. Loved that truck, put 70,000 miles on it and still think I shoulda kept it to this day.

Thats a great truck, I just sold a 2003 crew cab 4 wd with that same setup. I could have sold 6 of them if I had them, I also had 2 duramax's before the 8.1 gaser, the allison is awsome.

I Had an 01 Dually CC, it didn't have the allison, It had a "New Hyatt" 6 sp Manual, 1st gear could pull your house off the foundation. I got tired of looking out for fenders so now I have an 04 Silverado CC with a SuperCharged 6.0, Thats how they should come from the factory (over 150 mph :) )

I was looking at this setup but the mileage scares me off, but its only 1/2 mpg diff over the 6.0 so go for the power

I have the exact same truck and I love it!! It does love to drink gas but it rides awesome and it definitely pulls like a horse!

I know they used it untill 2006. 2007 might depend on what vehicle you are looking at.

I have a 2004 Chevy Suburban with 8.1L - 3.73 and 130k miles on it. Driving normal on highway at 70 to 75 I get a solid 14 mpg. Towing a 32' travel trailer that weighs in right at 10,000 lbs I get 8 to 8.2 mpg and you forget it is back there unless you are in hilly terrain, then the transmission shifts and you remember why. Ride is also great for a 3/4 ton truck. I bought mine because it has the cloth seats with the 60/40 front bench so it can seat 9. We have 5 kids and are Foster parents, so we never know when we may need the seating. Great truck, really impressive.

Typical GM, get something that works well and people like, so you have to drop it or change it. Oh, and mine will use a quart of oil around the 2,000 mark also.

never new they were available in the vans, might have to look into one of those.

Brian

I think the 2007 Classic's still came with it, I know the 2007 New Body style it was either the 6.0 or the Dmax.

The 8.1 and Allison are a great combo. A Hypertec tuner will give you a little more power in the over 4000 rpm range. I have a 2004 3/4 ton avalanche- 12 mpg around town, 14 hiway, 8 towing the Chris Cat. I didn't want a diesel when I bought the truck and it is built on the suburban chassis.

Wannabe

Mine is the ext cab version with black leather interior. :eekdrop: wow does that ever pop when you open the door. Also head room is unreal verses ford and dodge. For the money, this is it so far in my eyes. They even made a 4*4 van with this setup also, killer grocery getter, or soccer van for 12 kids. :party-smiley-004:
Thanks for the input. Makes me feel even better now.
B38:thankyouthankyou:

I have 230,000 miles on my 2001 C3500 GMC club cab, 8.1 with allison transmission. oil is changed every 3000 miles, amsoil is used in the transmission, as well as the differential. besides the truck looking like a 2001 model, it is in great shape. would NOT trade it in as replacement cost is out of control.

Can you get the Allison with a gas engine now?

I loved everything about mine except the mpg.

Do that again....drop air press in rear tires to 20 psi, you win.

I have 01 2500 HD CC with the 496 Allison, love the truck, s hitty gas mi but it doesnt matter as it's not a daily driver, just pulls my boat or race car, sits there otherwise. If you roll into it and stay out of the torque management it will haul azz. Some guys at the Diesel Place get a custom tune that gets around the torque management and they will really fly. Mine has a cracked exhaust manifold and sounds s hitty when cold, anyone else have that prob?

I have that in a 05 dually

Got 8.2 towing a 42 Fountain from Chicago to Louisiana and back,,,, 2000 miles for the Tickfaw 200

Not my DD so I dont care about the MPG

Had a custom tune and it pulls anything I want

Wish they still made it as I would like to get a newer truck

What's nice about this engine is the torque peaks at 3200 RPM and the HP at 4200. I cruise on the freeway at 2500 RPM but when I see a good hill coming I drop down to 5th and run the motor up to 3200 and it pulls right up the hill with a load. If it's not enough, I have plenty more RPM's & HP until I have to go down another gear. I've never had any reason to wind this motor up to get power like the smaller 6.0's. It's just a nice lazy BBC with plenty of power to pull.

Getting rid of this motor in the HD trucks was a stupid move on GM's part. I'd love to buy a new truck but I don't want a diesel so I've maintained my 2001.

2005 3/4 ton Avalanche with 8.1. Same story here and glad I got one of the last ones around. I get offers on my truck all the time from diesel owners looking to get back to gas. 14-10 mpg no matter what it does and a quart between 5K oil changes. If they did offer the Allison with this truck it would have been a much bigger seller I bet.

Pulls my 35 no problem and a comfy daily driver.

2008 was the last year you could order an 8.1L and allison in a GM truck.

Just a nice big quiet engine truck with great pulling power and years of trouble free operation!

Everybody who owns one and uses it for towing and such loves them, except for the mileage sometimes.

Sometimes 8.1L owners/boaters don't realize how much Raylar works with 8.1L truck owners on power and torque upgrades. The Raylar BCK102 kit with our aluminum heads and our BP202 camshaft and a good ECM reflash will make a torque monster out of an 8.1L truck and in most cases with good exhaust upgrades like our stainless long tube headers will take the horsepower up around 500HP and the cruising and towing mileage actually improves. This engine stock makes about 320-340HP and about 450 lb/ft of torque and after mods like this customers see 500HP and 600lb/ft. of torque!
Customers we have worked with over the years on such upgrades always say they don't recognize their own truck once they have made these type of improvements. Lets face it a stock engine making only 320 hp from 496 cubic inches is pretty pathetic!

Best Regards,
Ray @ Raylar

Mine is a 2001 3500 8.1 4x4. I love the truck. It has 107,000 miles. Because it sits alot, the brake lines just had to be redone and I recently did the exhaust. I put a cold air intake on it, re chipped it and gibson exhaust and it runs like a champ. As all have stated, it is thirsty but it rides and pulls like nothing else. Good luck with yours!

Does that 500HP/600TQ kit come with a built transmission? I know that you can limp the allison transmission if you put that much power to it. 450 HP is about the max the allison transmission will handle.

Nope.

Bummer they stopped making the 8.1, seems like something that does not blow-up is what GM needs to keep, not this junk 6.0Ltr, every time I use my buddy truck I come back and say how much noise can a motor make before it reaches temp. Piston slap forever, just a plug.:poopoo:

Getting rid of this motor in the HD trucks was a stupid move on GM's part. I'd love to buy a new truck but I don't want a diesel so I've maintained my 2001.[/QUOTE]

We have many customers with stock Allisons behind the 450-500HP Raylar kit upgraded 8.1L engine trucks with no mods or upgrades to the Allisons other than programming changes made in the ECM's and I have heard of a few who done Allison upgrades but I believe a few of those were done becuase they, drive them like they stole them, race the trucks or use them in tractor pulls and such. I am not an Allison expert by any measure but I think its a pretty strong transmission stock unless it like any transmissions has mechanical problems or issues to begin with.

Best Regards,
Ray @ Raylar

Did you (Kurt) have problems with a 4L80e? I have one behind a carbed 454. I just use it to tow but, I'm happy so far. I bet i don't get 6 mpg. lol

yes, blew it up, old haul truck busted forward drum and destroyed trans. Had to buy differant case and rebuild. Bummer. After rebuild it was OK. but for how long??

Plus it always lugged when towing, needed a another gear i always stated. LIKE A ALLISON:party-smiley-004:

Keep in mind that when guys talk about hp limits of stock allisons they are usually talking about diesels so the actual load is much higher for the same hp numbers when comparing i/e- a 450-500 hp duramax usually makes 1000 plus ft lbs of torque. The 450 hp isn't killing the trans, the insane torque is. A 4l80e can hold 450 hp/and corresponding tq that a gasoline engine can make with some modifications, Smitty

You are probably correct. I have an 2004 Duramax/Allison and was told anything more than the chip I have on it now and I would need a new transmission. Thought it would be the same for the 8.1 as well.

I just thought it would be the same for the 8.1 as well.

The allison is one smooth shifting transmission though. I love it.

I have had 4 duramaxes and my 02 I had I turned the programmer up to 135 hp over stock for a few days and slipped/limped the allison several times. I keep the tunes on my current 08 under a 100 hp over stock and let off while shifting momentarily. I build transmissions as a business and plan on pulling my allison soon and doing some upgrades/ plus a billet multi-disc tq convertor. By the way, I can get multi-disc convertors wholesale (of equal quality)if anyone wants one for hundreds less than than Banks/ B&D/ ATI/suncoast charges, Smitty

Thanks for the tips, always good to know these things.
B38

B38- Are your spark plugs new? They make a difference in the 8.1's and only use the AC delco's- Not Bosch or E3's.

Wannabe

had an '01 GMC HD 4x4 8.1 Allison
great truck
watch the oil level some drink more than others
8 towing 13k+
10 around town
had a wester's tune in it and used to have a blast smoking ricer's and wannabe ponycars from the 90's

went Dmax (twice now) and not looking back as there is no comparison towing heavy

I always use AC Delco plugs, best so far in my eyes, also delco oil filters are quality. I plan on a complete tuneup before i haul the Bertram. even change the gearlube. who hoo I like my truck. Drove it to work today, what a stumppuller.
B38

Don't sweat it. When that gasser blows you'll drop a Duramax in it(if you're smart :lolhit: ).

I do agree, just have to get GM to put the duramax in the burb. For large families towing, the 8.1L burb is the best bet money wise. The Diesel excursion is about twice the coin for comparable age vehicles. Got my 04 with 120k on it a year ago for $13k, Excursions w/ Diesel were $25k and up.

I added a forth row to my 04 so it now seats 12, which is good as we are a family of 11. Not many options out there for people like me. Then again, not many people out there like me! LOL!

Brian

Do you know there is a shop that will do that conversion? Google duraburb or something.