What is the best size of tire?

[68shortbedinmo]

Hello
I have a 68 shortbed and I have done a half hanger flip in the rear and cut one coil in the front and I have some 15"x7" wheels for the front and 15"x8 1/2" for the rear. I was wondering what would be the best tires to put on them? I don't think I want too tall of a sidewall but I definatley don't want a rubber band either thinking maybe 60 series ? Any suggestions or pictures of your setup would be appreciated.
Thanks

[tnlprt]

8.5 rims all the way around 235/75/15 on front 285/70/15 on rear

[tnlprt]

15X8.5 wheels all around 235/75/15 on front 265/60/15 on rear

[tnlprt]

15X7 on front 15X8.5 on rear....225/70/15 on front 285/70/15 on rear ...Stock ride height....I have some new 295/50/15 tires but they will not go on till after our annual cruise and burnout contest