These are steel plates used to weld into your 1973-1977 4wd F250 highboy frame to get rid of manual steering or power assist steering and install a greatly improved 2005-2008 F250/F350 power steering gear box. This requires you go to crossover steering at the same time. The 05-08 SD box uses a 3/4" 36 spline input shaft- the same as a 1978/79 steering box. If you already have a 1978/79 F250 4wd steering box conversion, your steering shaft will 100% bolt right up to this.
 
I have not tested these with original leaf springs. This conversion likely will not work with front leaf springs. 
 
I only sell the flat steel pieces, the machined spacers, and the metric hardware to install the box. This is by no means a bolt in kit nor does it include the steering box.
 
You will need to cut your factory cross member as pictured- please not this is a good amount of cutting and welding. These are all of the new steel pieces to box in the cross member and mount the newer steering gear box. Fabrication skills are required- this will just save you a ton of guess work. This was painstakingly designed and redesigned on CAD software and cut out on a CNC plasma table so as to be a precise and quality fit. It was entirely designed and tested here in the USA. I use it on my 1974 highboy to this day.
 
The main plate is pre cut with 3 holes that correspond to your original power steering box holes. bolt this plate on the outside of your frame first and use it as a template to drill the 2 other super duty box holes (9/16" drill bit)
 
 
Lares part number 11610 or 1610 is a great source for a steering box and about $340 on rockauto. A factory height pitman arm works well for most applications. Moog K440027 is about $25 for example. You can use a chevy 1 ton tie rod end.
 
The parts in this listing are included in my 2005+ super duty axle conversion kit for highboys.