I'll say it again, 2 totally different systems. A "factory production rear steer vehicle", such as one of the 16,000 made Silverados produced between 02-04 or an option on Honda Prelude or some others, is only steering 25% or less of the travel of the front axle. And at highway speeds it is not able to steer even 25% but instead just enough to keep the vehicle stable, which is the intended purpose.
Completely different systems and purposes compared to the backyard hillbilly rear steer that you 2 seem to be so passionate. The creator of this heep also added to the frame which is also a no-no. If I was him I wouldn't even sell it as road worthy and have the next owner sign a waiver or he's leaving himself open for a lawsuit. On trucks, anywhere between the front most and rear most spring perches is an area of the frame that should be un-molested meaning no cutting, welding, ect.
You might like it, that's fine. This is a forum full of opinions, mine is it's a useless rigged up truck that the only item of worth left to myself and some others is maybe the cab.