what's involved in placing larger rear drums on 90 model standard duty chassis?

Hi all

I have a 90 model z71 reg cab with the standard duty chassis. I was wondering if there's any way i can put the larger rear drums on it to make it stop a little better (haul a tractor, my work truck) anyway, i'd rather not convert the rears to disc, i was just wondering if yall have any ideas to make it stop better?

THanks

TB