Could be just me or the photo angle, but looks like the box shaft is not at the same point as the idler shaft. The pitman and idler appear to be the same length, but pitman APPEARS to be further back than the idler
Box maybe not a direct interchange for the 605 or 800, as in mount point to shaft?
Box maybe not a direct interchange for the 605 or 800, as in mount point to shaft?