I'm installing a rear spring kit from Total cost involved.
They said the directions with measurements for a 59 would be included.
After 3 phone calls they told me they don't have the measurements for a 59.
Setting it up now. Please look at my pictures and see if it looks ok.
TIA

 

Back spring mount is in a factory hole. I haven't drilled anything yet.

 

There is a thread from about a year ago detailing this same installation. The guy had issues with TCI putting the alignment hole in different locations on the two spring sets. With that in mind, make sure your axle housing is exactly perpendicular to the frame rails or your truck will crab-track going down the road.

As far as location is concerned, I would mount the bed with fenders back on the frame, pop on a wheel and tire and see how your rear tire looks. Since this kit can be bolted in, it should be a relatively simple matter to mock up your parts and make sure the location of your rear axle is just where you want it. Now is the time to resolve all of these issues before your installation becomes permanent.