Mike, The information that Fibonachu references is good for the tire sizes, but doesn't actually specify the wheel dimensions. The "Wheel" section (#5) that should be in the 1959 Chevy Truck Data file is missing from the file unfortunately. The below snap shot with wheel dimension info is taken from a
1959 Chevrolet Pickup dealer handout. That document lists Standard wheel size as 15 X 5.5" with a second Maximum wheel size of 17.5 X 5.25".
That too is only partial info. A check of a 1933-62 Chevy Master Parts and Accessories Catalog lists the following wheels for 1959 1/2 Tons:
GM# 3715441 - 16.0 x 5 (specified for 1954-62 1/2 Ton)
GM# 3736621 - 15 x 5.5 (specified for 1957-61 1/2 Ton)
GM# 3724684 - 17.5 x 5.25 (specified for 1956-59 1/2 Ton)
Guitplayers pictured wheels with the 3 spring clips to hold the original hubcaps are correct from what I can tell and will support the correct hubcaps for your 1959 3100. The next step is to figure out which of the wheels you intend to use and then go from there.
