Where is the best place to put the filter, before or after the pump?

Generally filters should be after the pump. It is easier for pumps to push rather than "suck". There should be a strainer before the pump to prevent debris from damaging the pump.
There are always exceptions and If the filter has an extremely low pressure drop and large area it can be used before the pump. But I would caution that the system should be designed accordingly.


TTFN
Mat

off subject a little and i dont want to hijack the thread but my car has 2..it was liek that when i bought it so i figured it was supposed to be like that...both of them are in the engine compartment. one is before the pump and the other is right at the carb...is this bad ....good....overkill

I have post my thoughts on this previously...I go for a filter behind the rear wheel...the draw back is any crap in it will show up in fuel supply to carb earlier...once the tank is clean its not a problem.
Stock filters are after the pump..this is because a car will not show up problems as soon...a piont that is good marketing strategy only.