Changing just rear tires for higher load rated tires?

Yes.both front and rear carry load. Just not in an equal fashion. Depending upon the truck, design etc, many time ALL of the.load goes to.the.rear axle, none to.the.front. If one knows wt distribution on the truck, this is not hard to do. While a dissenting generally.speaking for a go end pickup size has 1000 lbs more on the fa, one does not need the full psi of most tires in fronts vs rear with.A.max load.

Marty