Grigg,
...I assume pickup style, not singled out P30's.
Larry W.
Not sure what you're asking/assuming?
I will run the 14 bolt cab and chassis axle with normal single 19.5" wheels. Because it also measures ~63" WMS same as the original axle single wheel pickup; the pikcup wheels can again be used and will fit in the fenders.
On the 3/4 and 1 ton rear springs, 2" wide, the ~1/2" spacers go on the outside, makes the spring center spacing narrower.
On the larger trucks they use 2.5" wide springs with all the same spring hangers, pins, and shackles.
Grigg