72 Scamp wheel / tire recommendations

I have P245/60R14 on the back of my 72 Scamp with an 8 3/4 diff and drum brakes. Factory rally rims but where made by Wheels Vistiques to 7" wide and all of the addition was on the inside of the rim. I did have to roll the lip on the quarter panel. Don't think much more will fit without trimming.