These affordable solo seat mounting lugs can be used on any kustom build.  They are made in-house here at Choppahead out of 1" bar stock, drilled to 5/16-18 tpi (5/16" coarse thread), and are mitered on one side with a 1" end mill to fit your frame snug - allowing for clean welds.  We use these lugs on all our builds that have sprung solo seats.

Sold in pairs.