Searching for definitive answers: Z85 vs. Z71

[Southbound]

First post! I’ve already learned a lot here, and hope y’all can share a little more of your collective wisdom and help with a few questions.

 

I’m getting ready to order my first new truck ever, and want to get it just right. The basics:

• 2WD RCSB LT
  
• 5.3
  
• Summit white/cashmere
  
• Interior plus package, etc.
  

 

I don’t like the extreme rake that you see in these trucks from the factory, especially the RCSBs. Two-inch drop shackles will probably be one of my first mods, and I’ll likely remove the spacer blocks as well, for a total rear drop of 3.25”. Not interested in messing up my alignment with a leveling a kit--just want to level the truck out and keep it functional as a truck.

 

Here’s the problem: I’ve searched extensively (this site and elsewhere) and can’t find anything definitive about the difference between the Z85 and Z71 suspensions. Sure, I know the Z71 package gets you the skid plate, special air filter, tow hooks, and sticker. The extras would be nice, but not necessary. I’d remove the sticker.

 

This is going to be a road truck, and I want it to ride as smooth as a RCSB can. As near as I can tell, both suspension packages include 46mm shocks and a 36mm stabilizer bar.

 

Can anyone tell me if there’s any real difference between these setups? Specifically:

• Are the same shocks installed on Z85 and Z71 trucks?
  
• Do Z71 trucks sit higher?
  
• Are the spacer blocks the same thickness on both trucks?
  
• Do the Z71 jounce bumpers affect anything about how the truck rides or sits?
  
• Could I still do the drop shackles and remove the spacer blocks on a 2WD Z71 truck without problems? Am I going to get too close to the jounce bumpers?
  

 

As you might guess, I’m leaning towards the Z71, but not for the reasons most people go that way. The special equipment would be nice, but I’m more interested in upgrading to better factory wheels and not having to worry about chasing them down used.

 

I suspect that Z71 trucks are simply Z85 trucks with some mild extras and a sticker, at least in the case of 2WD RCSBs.

[spankrz]

from my understanding, the z71 has different shocks and struts, that would be stiffer. also, the ride height should be the same front and back as the non-z71 trucks. if this is only a road truck, i would steer away from the z71 and save the money and the weight of the extra skidplate. check the trading post here on the forum often, and wait it out a little bit, and you will have yourself a set of wheels shortly. in fact, there is a axel flip kit on there now i saw the other day, to put the rearend on top of the leaf springs.pair that up with a drop in the front and the right wheels and tires, it will look like a million bucks (after you debadge and demold and get the windows tinted)

[Southbound]

Yessir, I've read that in several places, but I'm hoping someone can tell me if they actually are different.

 

From Chevrolet's website:

 

 

• Heavy-duty handling/trailering suspension package (Z85) - "...includes 46mm monotube shocks and a 36mm front stabilizer bar..."
  

 

• Z71 off-road suspension package - "...includes 46mm high-pressure gas-charged shocks, a 36mm front stabilizer bar and off-road jounce bumpers..."
  

 

 

Does anyone here know if there are different part numbers for Z85 and Z71 shocks, or do these packages use the same shocks?

[RyanbabZ71]

Definition of different shocks

 

http://www.shockwarehouse.com/site/glossary.cfm

 

The Z71 vs Z85 are different shocks.

 

rockauto has a ton of listings based on the options your truck has but here are a few examples

 

ACDELCO Part # 540637 {#20955425}

ABSORBER,RR SHK EXTENDED CAB; 2 WHEEL DRIVE; w/ENHANCED TOWING PERF PKG(NHT) or CHAS PKG(Z85); LTZ Model Engine VIN 0 Code LMG; WT Model Engine VIN 0 Code LMG; LT Engine VIN 3 Code LC9 * Non-stock item--shipping delayed up to 5 business days

 

ACDELCO Part # 540638 {#20955427}

ABSORBER,RR SHK EXTENDED CAB; 2 WHEEL DRIVE; w/G M C "ALL TERRAIN" PKG(GAT) or Z71 "PLUS" APPEARANCE PKG(WEA); XFE Model Engine VIN 3 Code LC9; LTZ Model Engine VIN 0 Code LMG; WT Model Engine VIN 0 Code LMG; LT Engine VIN 3 Code LC9

ABSORBER,RR SHK CREW CAB; 2 WHEEL DRIVE; w/G M C "ALL TERRAIN" PKG(GAT) or Z71 "PLUS" APPEARANCE PKG(WEA); XFE Model Engine VIN 3 Code LC9; LTZ Model Engine VIN 0 Code LMG; WT Model Engine VIN 0 Code LMG; LT Engine VIN 3 Code LC9 * Non-stock item--shipping delayed up to 5 business days

 

see if this works, a ton of ACC Delco options (based on a 2011, 1500)

 

http://www.rockauto.com/catalog/raframecatalog.php

[Southbound]

I appreciate your help, Ryan, but I don't think that's right. The part numbers you list above as examples are for extended/crew cab trucks. I took a closer look at what Rock Auto offers, and found these listings for a 2011 with the 5.3:

 

 

ACDELCO Part # 540626 {#20955404}

ABSORBER,RR SHK REGULAR CAB; w/CHASSIS PERFORMANCE PKG(Z60) or 'OFF ROAD' CHAS PKG(Z71) or CHAS PKG(Z85); w/o ENHANCED TOWING PERF PKG(NHT); XFE Model Engine VIN 3 Code LC9; LTZ Model Engine VIN 0 Code LMG; LT Engine VIN 0 Code LMG; WT Model Engine VIN 0 Code LMG; LT Engine VIN 3 Code LC9

 

 

ACDELCO Part # 540633 {#20955414}

ABSORBER,RR SHK REGULAR CAB; w/CHAS PKG(Z83); LTZ Model Engine VIN 0 Code LMG; LT Engine VIN 0 Code LMG; WT Model Engine VIN 0 Code LMG; LT Engine VIN 3 Code LC9; WT Model Engine VIN 3 Code LC9; LTZ Model Engine VIN 3 Code LC9

 

 

I just called a couple of dealerships to run these part numbers, and they confirmed that 2WD RCSB trucks with the Z85, Z71, or Z60 suspension packages all come from the factory with the same rear shocks. RCSB trucks with the Z83 suspension package (WT trucks only, to my knowledge) are the exception--they run 35mm shocks. As an aside, I didn't know that you could even order a RCSB with the Z60 suspension.

 

If anyone out there can show me that this isn't right, I'd really like to hear from you before I order this truck-