It is my understanding that in order to install disc brakes on the 60's era trucks you have to use the spindles from a 71-72 truck. The aftermarket kits that I have seen use this setup.
Take a look at the kits offered by ABS in Orange, CA.
www.abspowerbrake.com. They also offer lowered spindles.
With regard to the steering, several aftermarket suppliers offer steering conversion kits. The problem you are going to have is to find or fabricate a pump mounting bracket for your 235 as nobody sells a kit. There are a number of postings about this subject. You can use the generator mounted pump but they can be expensive.
Fred
