looks like this was answered already , yea there is nothing wrong with going big, the problems occur when your trying to run big amps of small cap's , also buying big leaves you the ability to upgrade your system and not have to run another cap
it always surprises me how much people suggest capacitors. really people they do next to nothing. the lack of flickering headlights is because the caps degrade the performance behind them. voltage wise.
also you never stated a problem. if there is no problem why fix it?
and no 3.5 farads is not enough you need a massive amount to do anything positive at all and even then its detrimental to the charging system. This is not me saying they are good this is me saying that if you have a big enough one with next to zero ESR then Maybe it will do something for you.
Everyone that reads this, please do some research on how much energy is actually in a capacitor, you are grossly over estimating it.
