Spring Relocation Dimensions

I need a couple dimensions from those of you who have a spring relocation kit or have installed one or two. I've got a chassis that already had the front part of the relocation kit installed. I need to know what size the tube needs to be that is to be welded in the rear frame rails. Also need to know where exactly the hole is supposed to be on the front spring perch.... The ones on the chassis have three holes vertically spaced top to bottom.... Not sure which to use.

Thanks in advance.