I agree with Woogeroo.
I contemplated swapping to 5 lug on my '65 because of wheel selection. I now feel the swap to 5 lug is over rated, IMHO. A big part of the character of these old trucks is kept intact by not changing something just to make it like the "newer" stuff.
I just kept searching until I found some 6 lug wheels that I liked. Found some old 15x8-1/2 aluminum slots. Sure, it took some searching but that's part of the fun of this hobby.