Removing the front leaf brackets and crossmember... disaster?

[Meat_PoPsiclez]

I've been slowly working on a rear 4link 1ton swap on one of my 97 Sports, and am finally at the point where I need to make up my frame side link mounts. "Optimally" I'd like to have my upper link mounts right where the crossmember at the (now unnecessary) leaf mount is, but it looks like that bracket is structural, a major support for two separate frame sections?
I had planned to fabricate a new boxed crossmember (2x2 3/16 wall most likely), and would plate down some of the frame on either side of the existing bracket to tie into, but am I risking the frame splitting on me if I cut off those rivets?

 

[410Fortune]

if you cut out that crossmember and the brackets holding it to the frame, just plan to put it back and then some. Anytime I remove or hack out a cross member like this I build a new one to suit my needs and do my best to make it stronger then the original

Yes those rivets are adding a structural member to the frame
You have two choices: cut the whole thing out by grinding the rivets and saying a small prayer, or leave the cross member and just hack off the spring mounts, weld your new stuff to the existing x member....