Isx 2250 fuel pressure sensor for gauge

[aaronb]

I want to add a fuel pressure gauge after the secondary filter. That way I know when the filter needs changed. I have a fuel filter gauge for the fuel water separator. The FF5686 is huge so I'm assuming it should way outlast the fuel water separator cartridge. Especially if I'm running a 10 micron cartridge in the fuel water separator. Anyways, can someone tell me which port on the secondary filter head I can put a fuel pressure sensor after the filter? Thanks.