Man, I'm so tempted to try this.
I just did a 2/4 drop using belltech parts. But the rear dropped 4.5in (no spacer).
Rather not use the spacer to raise the rear and your solution looks like it would be perfect. Sketchy....but perfect.
Not sketchy at all actually. It isn't my idea per se, Rough Country (you know the company that sells lift kits) actually sells a drop kit that is nothing more than Grade 9 hardware and a 1/4" spacer to do this exact thing.
I just purchased the hardware from them without the spacer.
I seriously doubt a large company like that would risk their reputation and lawsuits over $20 worth of hardware.