Offset spring kits???

For 3/4" of offset, you'd have to cut a hole big enough for the whole hanger to slide into the frame 1/4". At that point the frame structure would be seriously compromised.

When I re-drilled, I welded up the old holes and cut the overlapped section of frame rail spot welded to the piece the hanger bolts to, so the hanger butts the frame with no interference. Then I just welded that joint to maintain the structure. I'm really surprised no one has done this?!

I bought a set of used 3/4" offset spring hangars for an a body . the guy said he didn`t like the way they fit his car.(got them dirt cheap, 35 plus shipping if I remember right)) the bolts were offset enoughe to get 3/4 w/ the existing hole in the frame elongated just enough to get the front hangar in, it changed mine just 1/2 hair shy of 3/4", the back ones were offset exactly 3/4, and I made the pads exactly 3/4, worked like a charm .
really didn`t help that much on tire clearance tho! ----bob