What feels like long ago, the W-Body/3800 world had a bunch of vendors. ZZP, Intense Racing, WBodyStore (WBS) and I am sure a few others I am missing. Intense Racing is still around but seems people only talk ZZP anymore (which ZZP is probably the most visible these days).
So here is the situation. Years ago in 2012, I bought WBS poly bushings for the dog bones and the clam shells on the radiator core support they attach to. To this day, the bushings are still fine, except in about 1-2 years, that bring and beautiful red faded and looks pink. So during Black Friday of 2022, I bought a set of ZZP and Intense Racing bushings. I figure refresh the ones on the blue Monte and add some to the black Monte and I am having a junk yard set of mounts sand blasted and powder coated. Since the WBS ones are still fine, note removing them from the mounts (as it will probably damage them), just stash them.
BUT, I thought I would use this as a chance to compare the two vendor products. Since the WBS is no longer in business and the only WBS bushings I have are installed, I cannot do this same comparison. Please note, I have NOT installed them yet or used them. Here is what I have found so far.

• For those into color, Intense Racing has a better/darker red.
• I don't have a tool to check material stiffness, but I am going to say they feel pretty close. ZZP might be a little softer.
• Common complaint with ZZP bushings is during install, people tend to over tighten the bolt going through the bushing and it cracks the aluminum of the brackets on the engine. I believe I see why. In each pic, the metal tube is pushed all the way to the table (so flush with the bottom end). So let me explain what I noticed and tried to capture.
  • It's not much, but was can see the ZZP tube is too short.
  • The Intense Racing bushing looks a bit short with a longer tube.
  • I have a tube that I removed from a factor rubber bushing. When we compare all three tubes, we see ZZP is short compared to the equal length Intense Racing and stock tubes.
    • Even though people installing should know to NOT over crank on that nut/bolt, the ZZP tube makes it super easy to just over tighten things. Yes, even with the factory length tube, you can still over tighten and crack those mounts.
  • We can also see the inside diameter of the ZZP and Intense tubes are a tighter fit vs the factory tube.
  • I did try to see if the factory tube might fit in the ZZP bushing. It is NOT a tight fit. If I wrap one layer of electrical tape around the tube, it then has a proper fit. But, that is a really goofy setup with electrical tape and I would be concerned about how big the inside diameter of that tube is for allowing the engine to rock.
  • The answer.... I could not find where to buy JUST the tube OR get the right tube stock and cut to length. But, I was able to talk to a friend at a machine shop, and now I have two hard metal correct length tubes.
• The upper radiator bushings:
  • Even though I have not installed, ZZP cornered the market on "ease of install". They are using a split design.
  • One might look at the Intense bushing and wonder "how do I install that". Well, this is how the WBS bushings were. I was a little surprised, but the answer is to remove the metal tube, use a lube on the bushing and a rubber mallet and pound it in. It worked crazy easy on the WBS bushings years ago (and I did not expect it to be so easy).
  • The inside diameter for the tubes (for the bolt to pass through) appear about the same on both vendors. But I did notice, ZZP has a thinner wall thickness. Not sure if that matters or not.

This summer I plan to get these sets installed on the two Montes I have. I don't expect a difference in performance (I expect they will perform/function identically). But, I do want to see if any color fade occurs.
So far, as of the writing of this, assuming neither experience the fade I saw with WBS, I lean on the Intense bushings to be better. The reason is they come with the correct length tube for the dog bone, the thicker wall for the radiator bushing and a better looking red to top it off. If you can consider it a negative, Intense does not offer any special discounts (not even on Black Friday) where ZZP offered there annual Black Friday specials.
Feel free to share your feedback.

 

Thats a really interesting comparison!

Its the first I've seen that issue with the ZZPs having a short sleeve - you'd figure they'd really watch that given the propensity of cracking mounts! I'd suspect most people just slap them on and don't even look at them that close to see if they have an issue.

I do wonder if ZZP did a re-formulation at some point. Their poly used to be notorious for being the harshest by far (and they also seemed to have the highest amount of poly cracking / crumbling which I suspect was tied to the high durometer material).

You don't seem to hear either of those complaints much anymore, and given you mention they feel about the same, I'd bet they swapped material somewhere along the line.


Are you running stock lowers?

 

I am running stock lower engine and trans mounts. The blue Monte still has it's factory ones and the Black Monte got new ones last year. I don't have any interest in going poly on those mounts (and poly is getting tough to source some days). I do have the LS4 King/Brandon Furches solid aluminum subframe bushings. Not an "any time soon" project on those (I just wanted to get them while the chance was available).

I am surprised myself with the amount of times I have seen people complain about cracking the aluminum ears when re-installed the dog bones with poly bushings that no one inspected the tube length. I saw one person shim it with washers. Ultimately, the real issue of cracking those ears is people going was too crazy with tightening those nuts and bolts.

I found with the WBS bushings, what seemed to tightened enough (did not crack anything) seemed a bit too much. Since the nuts are locking nuts, you don't have to go "nuts" tightening them, back off just a touch. If they are too tight, it negatively affects the ride. Maybe back off half a turn and that is perfect. Still feel it a bit, but not as much.

It will be later this year I hope to pop them on (waiting on some stuff to be sand blasted and then poweder coated).

 

These are still not on either of my Montes. But I had some updates. I have freshly powder coated dog bones and the upper radiator brackets. I went to assemble things. The upper radiator mounts, no issues. The ZZP bushing is two halves that piece together, the metal tube slides in and done. The Intense bushing, I used some dish soap to help lubricate it and a smack or two of the rubber mallet and it was in.

But, I was surprised at problems with the dog bone bushings. Both ZZP and Intense had issues.

- The ZZP dog bone bushing issue: I will first admit, the dog bones I am using are sourced from the junk yard and may be worn (such as the bushings could have been worn and oblong-ed the metal). When putting the bushings in, they would oblong the hole for the metal tube and fitting that tube would force the bushings out a few hairs. The shoulder on the bushings also did not meet with the metal of the dog bone (but that is a SMALL issue). The fact that putting the tube in caused a problem like it was, this prevents proper use of the bushing. Out of all the bushings ZZP sold, I have never heard of this. I could be a one-off and as I said the problem could be issues with the junk yard dog bones. I don't have pics of the oblong issue, but I do of the shoulder issue.

- The Intense dog bone bushings when placed in the dog bone, once the shoulder hits the metal, it leaves a small gap in side. The means the shoulders are too wide/thick! I am sure over the years Intense has also sold a lot of these. I am surprised at this issue. Makes me wonder if the dog bones had slight variations from GM and I may have caught an odd one?

ZZP Bushings:





Intense Racing Bushings:

 

So, to solve my bushing problem, I borrowed a Harbor Freight bench sander!

I don't have pics of the ZZP bushings, but to handle it, I sanded down some of the part of the bushing you never see that is covered by the metal of the dog bone. I also sanded some of where the bushings would touch (but not much). After some careful work and taking my time, got them to fit perfect.

The Intense Racing bushing, again, slow and careful work to not remove too much material and get the shoulder thickness reduced. Each pic is a unmodified Intense bushing vs a modified bushing.

I tested the fitment of both the ZZP and Intense bushings with a spare bracket I have in the garage.

Interesting that when I used the WBodyStore.com bushings years ago, I had none of these issues. As mentioned, could be an odd issue with the dog bones.