Tire and wheel issue

[nhr3]

I bought my truck around 1980. The previous owner, at some point had installed aftermarket wheels 15x10 in the rear and 15x8 in the front. Both wheels are from US Wheels and have 4 inch back spacing. This was in the beginning of Radial tires but the PO installed bias ply. I really liked the way the truck sat and now that I am reconditioning for the second time I intend to keep the same stance. In about 1990 I replaced the front tires with a radial that I am happy with the size (265/70x15). Now that I am getting ready to make a decision on the rear tires and need to figure out a good compromise on the size. The PO evidently had some issues with fender well clearance and had trimmed the rear bedside, outer lip to allow for more clearance. I have never had an issue there and have reconstructed the wheel wells to original. The old tire size is 31x11.5x15. The tire is similar to a mild all terrain of today. I am thinking a tire in the 29-30 inch outside diameter range and big enough to fill out the 10 inch wheel. does anybody have any input on possible size/brand etc?

One picture (the pretty one) was taken in about 1985. The other (the dirty one) when I started the rebuild in 2012.