71 Duster rear wheel and tire combination help

These are 15x7 with 4 1/4 backspace all way around. the back needs a 1/4 inch spacer but front is perfect. runnin a 225-70-15 on front and 275-60-15 on back

First 2 are with air shocks with 120 PSI
Last 2 are with air shocks with 0 PSI