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Tire size question for 2003 Avy.

Dialn911

Full Member
Joined
Dec 28, 2011
Messages
112
Hey guys,

I have to buy new tires and want to upgrade from stock 17s to aftermarket 17s.

I live in the mountains on a dirt road and actually use my All -terrains in 4X4.

I have a 2003 avalanche with cladding. I have a 2" levelling kit.

I've been looking all over for tire size recommendations for my truck with aftermarket wheels, but only found stock rim recommendations.

Does anyone know the largest size tire I can go height and width wise, with aftermarket wheels and a 2" level kit?

I was looking at 33x12.5...would this be right or is there a better option?

Thanks all.
 

Thor Hammer

Full Member
Joined
Jun 29, 2020
Messages
22
Hey guys,

I have to buy new tires and want to upgrade from stock 17s to aftermarket 17s.

I live in the mountains on a dirt road and actually use my All -terrains in 4X4.

I have a 2003 avalanche with cladding. I have a 2" levelling kit.

I've been looking all over for tire size recommendations for my truck with aftermarket wheels, but only found stock rim recommendations.

Does anyone know the largest size tire I can go height and width wise, with aftermarket wheels and a 2" level kit?

I was looking at 33x12.5...would this be right or is there a better option?

Thanks all.
This has probably been answered here multiple times. But I'll go ahead and bite as I'm fairly new around here but have plenty of knowledge on this subject. However with that said, go to Custom Offsets website. In the gallery section are 100's of avalanches with different lifts, tire and wheel sizes. Just type in a year of avalanche and they will all pop up.

With your leveling kit you will clear 33's easily. What you have to consider is the stock tire size (on my 2500 at least) is 30.5" with 3.73 gears. So going up to a larger than stock tire on stock gearing you will lose some low end torque as you have effectively raised the gearing higher. Just an FYI.

I'm running a tire that is 33.1" as that is what came on the truck from the previous owner. No lift whatsoever and it rubs the back of the fender well in reverse at full lock. Not a big deal. I also have a 8.1L so no comparison as this engine has around 75ft lbs. more of torque than the 5.3.

As far as wheels go, the stock offset is around +31mm for first gen avy's. I think. With that said you can get away with as much as a -12 offset. Some have gone more but it looks ridiculous as the wheels poke out from the fender too far. Lots of those rigs on custom offsets site.

A -12 will be about 1" of poke. I have a set of 17x9 -12mm offset Hardrock wheels about to go on with 295/70/17 Toyo MT's. I would have gone with a more positive offset wheel but I couldn't pass up the price. It'll rub a bit until i get a lift. And I plan to install 4.56 gears as well to get my power and torque back as close to stock ratio's as possible.

Hope that helps.
 

Dialn911

Full Member
Joined
Dec 28, 2011
Messages
112
Thinks for the info.

Believe it or not, there are only 3 photographs with my year avalanche with 17" rims.

Unfortunately,
there's not very much information at all for 17" wheels for my year avalanche on the custom offset gallery.

I did a search on the site here looking for recommendations for aftermarket rims and tire sizes, but the only thing I could find was discussions regarding largest size with stock wheels.

I must have missed the other discussions somehow.

I was wondering about 35s, I know a lot of people will run 33s, but I wondered 35s would be a better option.

I have a black bear tune on my ECM, so after I mount the tires I will have the ECM re tuned to match the change.

I plan on installing longtube headers and change the gearing to help with torque and towing.

Right now I have 373 gears, and plan on changing over the 410s.

I don't mind a little bit of offset, just not the absurd looking offset where the tires are sticking way out.

I appreciate you taking the time to answer. I figured I could get away with much larger size tires with a 2" level kit, I just wasn't sure what the options actually were.

I was considering going up a wheel size, but after much searching I came to the conclusion that 17" wheels seem to be the most versatile and well balanced wheel size for off road applications tire options and ride quality.

Just my opinion.
 
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Thor Hammer

Full Member
Joined
Jun 29, 2020
Messages
22
Thinks for the info.

Believe it or not, there are only 3 photographs with my year avalanche with 17" rims.

Unfortunately,
there's not very much information at all for 17" wheels for my year avalanche on the custom offset gallery.

I did a search on the site here looking for recommendations for aftermarket rims and tire sizes, but the only thing I could find was discussions regarding largest size with stock wheels.

I must have missed the other discussions somehow.

I was wondering about 35s, I know a lot of people will run 33s, but I wondered 35s would be a better option.

I have a black bear tune on my ECM, so after I mount the tires I will have the ECM re tuned to match the change.

I plan on installing longtube headers and change the gearing to help with torque and towing.

Right now I have 373 gears, and plan on changing over the 410s.

I don't mind a little bit of offset, just not the absurd looking offset where the tires are sticking way out.

I appreciate you taking the time to answer. I figured I could get away with much larger size tires with a 2" level kit, I just wasn't sure what the options actually were.

I was considering going up a wheel size, but after much searching I came to the conclusion that 17" wheels seem to be the most versatile and well balanced wheel size for off road applications tire options and ride quality.

Just my opinion.

Yeah, most rigs on there are 20" wheels. However, that doesn't really matter if all your after is how big of a tire you can fit with a 2" level kit. But yeah, you wont fit 35's without at least 4.5" of lift and lots of trimming in the front fenders. Guys with 6" of lift and 35's still rub a little after trimming.

What level kit did you go with? Did it make the ride more harsh/stiff? Did it come with rear lift blocks? I ask as I'd love a little more clearance but dont want to make the ride more harsh. Ultimately I want to convert the front end to coilovers and do away with the crappy torsion bar design. But sadly all I can find right now is the BDS coilover kit at upwards of $6K to $7K if you opt for the rear leaf springs. I don't like lift blocks.

The spindle lifts are another option and BDS has one for my 2500 for around $2K. But you gain very little suspension travel and still have to run the torsion bars.

Is yours a 1500? Thats awesome you went with Blackbear. He's the man. I plan to do the same after I bolt on some Raylar parts like cam and roller rockers. And port the intake. Those stainless works long tube headers are $weet if your local smog laws allow them. I live in Cali so its a no go for me. Post pics of the install!

Why only 4.10's on 33's? If you're going to go to the trouble I'd personally go with at least 4.56 if you plan to tow. And then if you bump up to 35's your gearing will be low enough that you don't lose much power.

I dont understand the draw to the tires sticking out as far as possible and rubber bands for tires. No off road ability. Just looks. Try airing down a 33 on a 20" wheel. LOL. Not going to happen. Must be a kid thing. Millenials...smh.

I agree the 17" is perfect. As with even a 33 there is enough sidewall to air down and get over rocks if you plan to mildly offroad and explore off the grid camping like I plan to do with my son. My favorite place to go is the Stanislaus forest up here in California. Lots of rocky forest service roads that lead to gorgeous rivers with excellent fishing and swimming holes.

Post up pics of your ride.
 

Dialn911

Full Member
Joined
Dec 28, 2011
Messages
112
The level cat I went with, is a 2" rough country kit that uses keys.
No complaints, I didn't notice any real difference in ride quality.

I always thought about going with 410 gearing Because that's what I always saw a recommended.

Don't know much about 4.56 gearing.

Right now I am trying to find some stainless steel long tube header packages on eBay to go with, but I don't think much of the sellers know what they are talking about.
The eBay compatibility chart will say the kit will fit my avalanche, but when I ask the seller if matters the vehicle is a 4x4, they then tell me it won't fit.

I am not sure that's correct, are you familiar with any stainless steel long tube header packages on ebay that will fit a 4x4 avalanche?

Did you know...
If headers fit a 2003, 1500 Avalanche, would they also fit a Z71 4x4? Or is there a difference in fitment between a 2wd and a 4x4.
 
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