What odd noise? The first kit that I installed was on my 74 Scout, which was my daily driver for a few years afterwards, and not once had any issues (or noise) from the shackle reversal kit. Installed a second reversal kit on my 73 beast and again nothing out of the ordinary. I have recently installed two more reversal kits on two other Scout, a 69 and a 78, both not mine. Not once have I heard from these guys about any "odd noise". Only praise on how well thier scouts handled after the kit was installed.
As a side note regarding my 74 consensus of the reversal kit. At one point, some time after I installed the kit, I drove it up to the rubicon. And the suspension handled flawlessly. During the travel back to camp later in the evening, traveling down hill, both front tires droped suddenly, about two feet, and the right front fang of the shackle reversal kit had hit and scraped the rock. Almost like a sudden impact. And everything held together as if nothing happend. Scout just smiled and kept going. A bandaid helped cover up the battle scare of a scratch.
**edit**
I need to drink more cafiene before I post. After re-reading your question about the "nose dive". I personally never had that type of experience in the two kits I had installed on my own scouts. And I have not heard from the other two regarding what you have heard or read. Only possible conclusion I could think of that could cause the "nose dive" is maybe real soft leaf springs. Idk