there should be a filter before and after the pump. this is why i stopped using aftermarket pumps because it took too much room and there was more room for error. when i build a turbo bike i now use the stock pump assembly with no modifications to the fuel system. all my fueling is done via ecm tuning. a modified fuel system is just another component that can fail. my first turbo bike build had your same fueling setup and it was a unreliable disaster.

there simply isnt room for two filters..if you had to choose which would you have ...before pump or after

doesnt the pump have a filter insert on the inlet side? if i were you i would just remove all the aftermarket fuel system parts you have and put it back to stock. the stock system will easily suport 6 psi boost and be a lot more reliable. this is the route i went after 2 turbo bike builds with aftermrket fuel system frustrations.......

turns out the pump has a built in filter.may return to stock fuel setup at end of season