I'm going to take a different tangent on this...
If loosing the steering damper at 40 MPH is a puckering moment, there are bigger issues that should be addressed. Maybe you were playing baja racer, in which case maybe it would be a noticeable failure. But if you are driving on a road at 40 MPH and the damper bracket failing makes a noticeable difference in how it drives, someone was using the damper to mask problems they probably didn't understand correctly.
The damper absorbs sudden movement, impact blows. Stuff that tears up steering gear boxes and cracks the frame where the steering box goes. Also slows the sudden steering wheel snaps that like to try and break thumbs. Doesn't prevent them, just slows them down a little bit.
At this point I am thinking you have a flawed lift and probably don't even know it. There are a lot of members here who run 3½" lift with no steering damper at all. Not just trail rigs, but people who daily drive them, thousands of miles a year, highway speeds (and beyond). I have lost a damper bracket once. Completely un-noticeable on the street and highway. Only noticeable off-road when one tire would catch a rock and snap the steering wheel to one side violently. I like my steering gear box and uncracked frame so I went and re-attached mine. Which was a stock bracket.
Back to yours. Sounds like you picked up a stock replacment damper for a Bronco and it doesn't fit. At this point you are now into the realm of PO (Previous Owner) modifications. There is no rule or limit to what a PO may have done in the past. Broncos have been highly customized with all sorts of stuff for decades. Sometimes well engineered and functional, sometimes using stuff from a scrap pile installed while racing to empty a keg PBR. There is no universal 3½" lift kit steering damper drop bracket for non-stock sized steering damper. We understand it doesn't fit. But there are too many different lift and steering setups for a 3½" lift to really have any idea what you are working with. If we could see what you are working with, maybe we could come up with an idea to fix it. But the mental picture has too many holes in it at the moment.