How many of you have installed the 20:1 ratio worm gear in your24:1 box? PN P4007612

My motor is at the machine shop so I'm using this time to replace some front end components. I just don't see how I could throw all this money into the drivetrain and not even bother to touch the 49 year old steering box or worn out bushings. Has anyone done this and is it something you can do in the garage or should I send it out? I just can't justify spending $600+ on a firm feel or flaming river box. Also any advice on what sway bar I should use (as I currently don't have one) for the 68 k frame and 73+ disc brakes. I currently have .890 TB which I think will be ok but any advice on that will be appreciated. Keep in mind I like a more firm suspension.