I think all the Z71 have the G80 Locking diff. Maybe an option on the Z85. I am sure there are more stuff in the Z71 package..

 

i've heard the axle is wider for z71. now that would be different.

 

try... How to Tell the Difference Between a Z71 & a Z85 | eHow.com and http://www.355nation.net/forum/lifting/18986-differences-between-z85-z71-4x4-models.html

 

I don't know the differences in the rear of the truck to give it a slight lift over the Z85, but the front has a different spindle on the two models. The position of the balljoints relative to the spindle centerline is different. That gives the truck an inch (I think) lift over the Z85. Tires like mentioned. Fender flares are different. Z71 has skid plates, or at least better ones. Z71 has a larger shocks.

Other than those things, yeah they are pretty similar trucks. Nothing different in engine/transmission specs. Brakes should be identical. I think you get the picture?

The dealer won't do an update to a Z85. If you want one, they will gladly order you one. :mrgreen:

 

Really the only diffrences are taller tires and shocks.

 

...and the spindles.

Tires won't equal the height of a Z71 alone. We Z85 owners are destin to a 'smaller' truck. LOL

 

If that is true about the spindles wouldn't the front CV axles always be at an angle unless the front differential has also been lowered? The CV axles are level on all 4wd trucks.

I've confirmed that there is only one part number for for the various suspension components on all torsion bar trucks. This would cover Z85s and Z71s. Tires give Z71s their height.

Have the dealer put on the Z71 wheels and tires and you're close enough. Even better, you can have them put on the newer 16" Z71 wheels/tires which are 32" overall in diameter.

 

I've seen pictures of the stock spindles between the Z85 and Z71. I don't recall where, but somebody posted pictures to end the debate between what is different.

The dealer doesn't charge thousands of additional dollars for "tires" to make the truck a Z71. It's a suspension package, to be more off-road equipped.

 

few little minor things...but the height comes from the tires...u get skid plates, flares, stickers...and maybe a few other things that im not thinkin off...but a 4x4 z85 is about the best way to go....u can add the extra for a lot cheaper then wat the dealer sells them for..

 

Would putting the bigger Z71 wheels/tires alter how the speedometer reads the speed of the truck?

 

Yes, the difference in speed is the same as the percentage in difference in tire size. A tire that is 10% larger means your speed is 10% off. Not just once, but across the range of speed. It's 10% off at 10 mph, 10% off at 40mph, 10% off at 60mph, etc. The odometer is off. The shift points aren't the same either. Maybe not a big deal, depending on the difference in size. My tires are almost 10% larger. It shifts pretty well, but now cruising through town overdrive is coming in way too early. I haven't had the PCM reprogrammed yet for the difference-but when I do it should make it shift more appropriately as well as correct the speedometer and odometer.

Again, there is more to a Z71 than tires. You will achieve a slightly taller stance with a taller tire, but you are going to sacrifice the fender well clearance as well as possibly rub.

What tire size is on your truck now?

 

P235/75R16

I actually am starting to like that size and I might just keep them. Maybe get some A/T tires, same size.

 

so what is a 08 off road is it a z71 or a z85 just wondering .

 

"Off Road" is the GMC Canyon version of a Colorado Z71, samething. If you look at the backside of the glove box door it will say Z71 along with a bunch of other manufacturer codes.

 

so even though its not a relatively cheap conversion, would swapping out the spindle from a z71 to a z85 gain lift? and if so would it throw off the CV angles? just wondering if one happens to pop up in a junkyard.

 

If your truck is 4x4, just crank the TBs a little bit to gain lift, and depending on how much you lift, you might want to drop the front differential by adding spacers between the diff body and the truck's frame.

 

im already cranked and body lifted. i was just curious. god i really need to post some pics. i have really failed in that department

 

Its possible, but not worth it at all. just put z71 stickers and nobody would ever know the difference.

 

I believe the Z71 is torsion bar suspension and the Z85 is coil also

 

4x4 Z85s are torsion bar... also the rare 2wd Z85 with the V8 is torsion bar.

All z71s are torsion bar


All ZQ8s and extremes and I4 and I5 2wd Z85s are coil