The voltage written on the capacitor shows essentially his margin of safety. Will give higher his strikes. You just increased the "margin of safety" capacitors, and nothing more. If you Google on the topic of power supply units to put capacitors with a supply voltage recommended almost everything, the only limitation here is the stock better to make reasonable, because the greater voltage capacitors, usually larger and more expensive.
About the increase in capacity is the Council correct in relation to the filters of power supplies, but not in other cases (say, if you significantly change the capacitance of the capacitor in the crossover of the speakers, you change the cutoff frequency and probably mess up the sound). In a traditional transformer power supply (not familiar with the pulse) the capacitor absorbs the ripple, there by increasing the capacity increases and the pulsation suppression, but at the start significantly increases the current of the primary charging of the capacitor.