73 duster 275/60/15????

Fisher said
Without moving springs you can fit a 275/60/15 with a 15x8 wheel with a 4.5" BS. I moved my springs in and will be running 15x10 with a 5.5" BS and a 28x10.5 /15 slick

Did you ever end up moving your springs to fit a bigger tire? Is that a costly thing to do?