If you get a set of rear springs off of an S10 with the Z85 RPO code, you will get the heavier duty springs. If your Blazer's like mine it has the "Smooth Ride Suspension" RPO Code YW7 in it. I have a set of Z85 rears to put in mine some time next spring. I'd like to replace the torsion bars as well as mine are soft in the front end.

All the torsion bars are the same length. The heavier duty the truck the thicker the bars were.

Uninstalled length of the rear springs is approx 51" From eye to eye

 

yeah, i know the Z85 springs are heavier duty, same as the t-bars he installed. but i want a little more lift. this thing squats in the ***, and never mind when i've got my big trailer on it, or my tools in the back!

and i just noticed on Wednesday (when pulling mt youngest brother's "94 Jimmy up on ramps) that my Blazer sits almost 2" lower than his truck (both stock). the designers @ GM ruined these trucks when they started listening to all the "office women" complaining about the ride quality of them. they're so soft 'n squishy now..........

 

Old Skool you need a set of Z85 springs.. That will fix your saggy butt!!! LOL

 

I also have the "Premium Smooth Ride" but mine is Zw7, and I dont really want to open a can of worms here, but it thought suspension packages were as follows:

ZW7 and Z60(full sized truck version) = smooth, touring suspension
Z85 = Handeling/trailoring package (stiffened rear end)
ZR2 and Z71 (full sized truck verison) = off road package (taller and skid plates)

the Z85 is equal to another leaf on the spring BUT no height gained. just takes more of a load to flex it... <-- is that what you are going for? more capacity? or am i missing the point of a z85 spring swap here? lastly, Z85 was only offered on S10 PU's, not Blazers. While the springs are heavier duty 9so you can pack more crap in the bed) the average day to day weight on them is FAR less than in the back end of a blazer 9not really that far but still0. Anyway the Blazer had the Z82 option in it's place...

Also "TrailBlazer" 2 gen blazers came with the Z85 standard FYI.

 

Your right it is the ZW7 suspension I have on the blazer. I was just thinking that if Old Skool went with the Z85 rears and maybe a 2" shackle lift that it would help his draggy butt. LOL

My sonoma has the Z85 rears and it sits up pretty high, but then again it doesn't have the extra weight of the Blazer on it. But still it would help. Maybe a mix of Z85 main springs and Blazer secondaries?

My problem with my Blazer is that the springs are getting old. I have an extra set of 2000 S10 Z85 main leafs sitting in the back of the truck to be put on my Blazer at some point next year.

When I got my Sonoma all the secondary leafs were broke in the spring packs. So I bought a set from the JY and just used the secondarys and kept the mains. Because I couldn't get those darned shackles loose. So I just rebuilt the spring pack. That was fun in 20 F weather. LOL Looking at them and the stockers on my Blazer there is a noticeable difference in the thickness of the main leaf.

 

hmm. this is worth checking into. i think i will poke around a bit and see if i can find WHY Z85's are better so i can shop a pair out with confidence i like the idea of it, i feel my rear is too low, and it looks like my leafs bow up like a W instead of curving up in a U shape. Maybe this is what the Truck Doc ordered ...

 

ABN: thats what my rear leafs look like on the blazer. The ones on the sonoma are nice and U shaped.

That might just be a component of that "Gentle Ride" crap they put on it.

I just went and looked at the S15, nice and arched. Just like its supposed to be.

 

i was looking at 1 for 1 springs off a comperable blazer, but the Z85's look promising. also looked into "Husky Spring" Leaf Helper additional support leafs from Rock Auto. looks like a kit of 2 (1 per side) for your springs to stiffen them up. as the leaf compresses, the spring helper pushes it back down. i guess its like a new take on traction bars

anyway, for $95 it would make the rear end handle a lot heavier load AND hopefully shore up the springs a bit.


MAN we could not be farther from the OP's torsion bar install sorry for the

 

The OP was nice enough to post those part #'s. Now I know what to look for.

Yea we sorta got off topic but it is spring related. We just moved a bit farther back. LOL

 

As a side not now that ive been thinking about it..... i think putting these bars in just so happens to be the equivalent of a t bar crank. how much im not sure.

when i put the Z bars in i noticed that bars were indexed so the keys hung down a little bit below the cross member without the adjusting block or bolt in. My stock bars were indexed so that the end of the key was up in the cross member without the adjusting block in. That is just how my factory keys lined up with the head on the ZR2 bar.

with these bars installed & the torsion bar adjusting bolts turned almost all the way out (1 or 2 turns to level it), my caster & camber adjustment cams are at their max setting. Funny thing is that neither the cv shafts or lower controll arm seem to be at any kind of extreme angle.

with my 2 inch body lift & 31 inch tires I measure 36 inches to the bottom of the fender lip & 12 1/4 inches from the ground to the bottom of the frame right below the front door hinges.