The following quote is from TDR member '956Wheel. He posted the info on 07/19/2002:
"I just put a set on my '95 a couple months ago. Easy to do, a good floor jack does the trick... be careful, you can get bit if you are not careful.
As for the ride, those little jarring bumps are softer now, the rear suspension is "progressive" with the velvet rides. They lowered the truck approx. 1". I towed with them and the ride is smoother. Bottom line IMO they are worth it.
BE CERTAIN THEY ARE THE RIGHT ONES... . the first set was packaged in the wrong box, too narrow and the holes were 9/16" rather than the needed 5/8" and doing any job twice SUX... IMO
Mike"
Here is the link so you can check it out yourself,
https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=51703
This was posted by TDR member Posm on 06/19/2002:
"I have the velvet ride shackles and they have their limitaions. First, they help a lot unladen on rough roads. I live at the end of a one mile private gravel road that has a lot of washboard. they help with wheel hop/axle wrap in this situation. When they are loaded they collapse and have no effect on the ride and may actually raise the ride hieght an inch or more. They do lower the unladen ride hieght about 1/2 to 1 inch. I wanted to lower the height on my 4 X 4 to give extra clearence for my gooseneck. I did not accomplish enough of a height change to help. "
Here is the link:
https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=49629
Posted by TGreco on 04/06/2002:
"I installed a pair on a co-workers 2002 GMC Dually with the Duramax Diesel. He claims the ride is alot softer and rear end (his) friendly. They lowered the rear of the truck about two inches. The lowering of the truck I did not like but it did not ride too harsh when unloaded. He is happy with them and that is whats important. Hope this helps"
Here is the link:
https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=38596
Given the three instances above, I think my comment is substantiated by facts and qualifies to be more than just a rumor. Granted not everyone reported this problem. Perhaps they did not pay attention? perhaps all velvet ride shackles do not perform the same? I do know that by the TDR members comments that some have experienced a decrease in rear ride height.
As the one thread suggest, perhaps they are adjustable? I cannot comment on that since I have never seen them in person. I think if they are adjustable, it would stiffen up the shackle negating some positive reasons why they were installed in the first place. As I said this is just my opinion, and perhaps they are not even adjustable.