I decided not to mess with that, and just added the filter in the hose to the fuel pump. Not a pretty installation on late-models, it's a short section of hose so I bought a section of 1/2" ID at NAPA and looped around before going into the pump.

 

If you put a second filter in-line between tank and pump your in tank filter (ie. the pick up screen) can still get clogged. Especially with 25 years worth of crud in there.

 

True enough; a plugged screen could cause problems but wouldn't cost $150 for a new pump. I had removed the screen prior to this and knew it was clean, but brittle. I was more worried about sand than goop. The tank appeared clean but with my previous bad experience and a brand new pump, I wasn't going to risk it. New screens are $30, vs $8 for the external filter. I also wonder if the screens have been updated for modern 10% alky gas.