Once I got my stock brakes rebuilt and adjusted over a period of time, they work just fine. I don't drive this truck like a bracket racer 'tho and I'm not sure disc brakes would give any improvement since I've opted to keep bias ply tires and inner tubes.
If I were tempted at all, I might upgrade to drilled drums to get heat and water out quickly
51-70 Brake Drum - Front/rear - 1/2 Ton - Cross-drilled And a heavy duty replacement when I'm ready for new shoes
Brake In A Box Brake Shoe Combo Kit 
