Egged out 1967 K member idler arm attachment fix needed.

RedFish, grafting on or fabricating a '68 bracket is looking better to me by the minute than frigging around snipping out a second bushing from thicker stock, and trying to ream a perfect '67 hole free hand with car on jack stands.

I haven’t seen any other style idler arm brackets except the 1967 type. So I having a bit of a problem visualizing just how much the standard multiyear configuration differs from a 1967 setup. I have looked at '68 idler arms on various part suppliers web sites, but without the seeing the '68 K member’s bracket I’m having a hard time visualizing the contraption.

Does anyone know the dimension of a 68 through bolt, is it special built, or an off the shelf grade 8? Dose a new bolt come with a new non '67 Idler arm? Could my '67 bracket be re-drilled to accept the '68 style mount?