Better to pull fuel through than push it through.

Ayuh,.... Agreed,.... that keeps the crud outa the fuel pump,....

I use a bulkhead style mount with a WIX 33522 water separator/filter with -8 lines and I pull through with my mechanical pump. I boat on big water and don't want to be stranded because I got some bad gas. It's a big filter but definitely worth it. It has a lot of filter area and filters down to 10 microns with a drain to check for water.

Most will agree pull thru with a mechanical pump. Mechanical pumps have thin little plastic type membranes that act as valves. It's better to filter out debris before going thru them. That said, out of curiosity of if a fuel/water seperator works in push thru, I made my system this way. The water seperator seems to be seperating water exactly as it did as pull thru.

Reason for checking is for electric fuel pump set ups. They don't pull fuel worth schit as we know, however to have a filter/seperator before the pump usually increases height the fuel has to go before pump can access it.
So, inline prefilter before electric pump, pump itself, and then to (usually up to) a water/seperator filter seems to work fine. Just make sure the sperator/filter is rated for the psi given, even thoug most are.

i pull through the filter before the electric pump[a1000 aeromotive] but the filter is equil or below the tank and the pump is about 5 inches below the filter.the problem with my setup is that if i need to replace one of the pumps that engine needs to come out first.