1971 2wd conversion

[BGREEN]

Hey guys, I am new to the site and I could use a little help. I have a 71 K5 that has been converted to a 2wd. We have lowered the front using 3" drop spindles and a 5 inch flip kit to lower the rear around 5". The current tire wheel combo is 15 x 8 rally wheels 275/50/15 on the front and 295/50/15 on the rear with a 15 x 10 wheel. I am having some issues with rubbing on the rear and could use some suggestions.....
Can I get away with a smaller rear tire on the 10" rear wheel or should I move forward with a new wheel/tire combo?

thanks