GM originally came up with their own version years back to help fix wheel hop but it didn't really change that much and if they weren't greased they would squeak.
These inserts basically take up the voids in the cradle mounting points and make it more ridgid. Naturally the downside is more road/driveline noise but it was worth it to me. I've had my set in for a few years and they still look new. I can't say much about the wheel hop but the rear of the car definitely feels more planted.
There should be some threads with pictures and more info around on these as I didn't design them. I'm just having someone remake them again since they are no longer available
Is CF erasing threads now? I wanted to post a link to my thread but most of my posts/threads are gone.
Anyways, I always support cradle bushing. Next to the Maggie they probably made the biggest difference in how my car feels. And makes it MUCH more fun to drive. She handles better with them and gives you more confidence in corners. Wheel-hop is a non-issue for me.
They did introduce some rear end whine, but higher weight gear oil quieted that down. At interstate speeds, 65+, the diff is quiet.
Now to make a 06-07 version...
add me to this order...asked around, this is a good upgrade.
Did some digging on this...
Seems like GM made changes to the 06/07's to help out the wheel hop and as a result the bushings weren't going to make much of a difference.
So basically no one ever addressed it.