I wanted to run cool fuel thru the pump but now i`m not sure the pumps are that good at sucking .
maybe it should be on the pressure side?
Thoughts ?

If the filter head is above the pump I see no issue pulling fuel through the cooler. I assume currently there is not an issue with the pump drawing through the filter.

I`ve looked into this and those Pumps are gravity fed and don`t like to suck.
I`ll be changing that over to cool the return fuel.

Pumps in general don’t like to suck. Diaphragm style pumps can do it best. Gerotors can do it, but are sensitive to debris and the manufacturing tolerances. Centrifugal pumps can’t do it at all.

I would put anything that’s not a filter downstream.

Least restriction possible to inlet of electric fuel pumps.

At this point in life I’d settle for either one! 😂

suck, Mary Beth, blow means suck. not my joke but still funny.