Another tire size help question

[SBTork]

Im doing a 4.5/6 or 5/7 drop on my 82 C-10 and im wondering about tire size on a 15x8 rally. I like the way the 255/60 15's look, but I think they may be a bit small as far as sidewall. I know they're 27" in diameter, section width is 10" and section height is 6". I was also thinking about 265/70 15, but I think they may be a little big. They run 29.6" in diameter, section width is 10.4" and section height is 7.3". I like a little bit bigger tire, but I think it's too much with that drop, it'll just look odd.
So now im here, wondering what other options are, or if I should just go with 255/60 15's and just shut up. Any suggestions?