Bed floor mounting. The correct way??

[Wildman65]

I'm currently replacing the bed floor in my 1965 short bed fleet side. I'm putting a new front panel in and all new cross sills. What I had to start with was somone elses floor that was pretty shady and it didn't have the correct cross sills. I also have all new stainless strips and mounting kit. I'm going to have to do some modifying of the widths of the boards because my wheel wells are widened. I'm just looking to find a detailed schematic of the mounting to work with. Any help would be greatly appreciated.