[Jim B]

Never having done that myself I would start by placing the secondary shoe and lining over the primary on the bench and look for the differences. If the reason for the drum not going over the brakes is the different thickness of the lining you may be in the area that arc grinding the brake shoes may be required for correct lining to drum contact. (am I showing my age??) If the reason is a different shoe and you choose to grind be sure the adjuster end has proper engagement in the finished cutout and be careful not to weaken the adjuster end by excessive material removal. Use of a brake drum gauge will give you an idea of the amount that is necessary to remove. That said why are you going this route anyway? I have no prior experience on your particular combo but increased lining area may result in an unsatisfactory higher pedal effort and improper lining contact will reduce braking performance. Can't source premium/high performance brake shoes to increase your stopping requirements?