Need Help choosing Rim and Tires

[hussler]

Hi Guys I am new to this site and i'm sure you all sick and tired of this question which rim and tire set up will work?? Well i just bought a 1968 Step Side, currently it is a 6 bolt set up that i;m converting to 5 on 5 this weekend mostly because of the rim choices... The truck is lowered 6" in back and 4" up front. The rims on it now are Billet Specialty the front are 225/70/15 x7" wide 0 offset 3-1/2 B.S. Rears are 295/60/15 x 11" wide 0 offset 6" B.S. (the truck has been mini tubbed) I would like to go with the widest front and back set up, i would like to go with 20" x 10? anybody with some advice please chime in on what you have done or what i should do.. The first pic is from the tubbed area to the inner edge of the rear fender, second pic from ground to fender, the other is of the front...
Thank you!!