Remember that things are going to settle a bit after you drive the truck a few mile.
I went back and checked the size and diameter and I ran 195-60- 14 tires on 7 inch rims on the front of the 48 for years and they fit the wheel well pretty well and looked balanced with the 255-60-15 tires on the back on 15x8 inch rims.
This I believe was when I had 205 tires on the 14 inch rims.
URL=http://s173.beta.photobucket.com/user/mr48chev/media/1948%20Chev%20pickup/2008-01-02-0933-02-2-1.jpg.html]

[/URL]
I'm thinking that with the dropped spindles you are going to have to run at least a 15 inch wheel to be above the scrub line though. I've always viewed dropped spindles as a way to correct a suspension that sets too high after the vehicle is already together without using dropped springs rather than a starting point on a build.