I need a shop manual for my '64 C10 but I notice from 'Chevy Duty' that I would need a 1963 full manual plus a '64 supplement - total cost $50!

For basic nuts & bolts stuff (suspension, brakes etc) can anyone tell me if I REALLY need both, or which one would be sufficient (presumably the '63 has most of the basics covered)

Are there any cheaper sources for these books?
Thanks, Simon