Got around to changing the fuel filters today and wanted to share what I learned. Specifically, the part numbers and specs of the main primary and secondary filter and the filter with a drain valve. I planned to use the one with a drain valve as the secondary fuel filter but decided to go with the main 3118/3120 combo.
It wasn't clear if the 3418 was spec'd for primary or secondary filtration, so grabbed the specs off the website and offer them up. Made my choice before reviewing the specs but with hindsight, the 3120 would still be the choice as the finer filtration seems better. Since they are so easy to swap, if I think water is in the fuel it's a 10 minute job to unscrew, dump, refill, and spin back on. Maybe after a tank or two of bad fuel, I'll decide differently. It's going into the spare parts bin just in case. lol
Napa 3118 Primary Fuel Specifications
Contents 30 Micron
Fuel Filter Gasket O.D. (Inches) 3.555 in.
Fuel Filter Gasket O.D. (mm) 90 mm
Fuel Filter Gasket Thickness (Inches) .26 in.
Fuel Filter Gasket Thickness (mm) 6 mm
Fuel Filter Height (Inches) 7.827 in.
Fuel Filter Height (mm) 199 mm
Fuel Filter Inlet Thread Size (Inches) 1 in. - 12
Fuel Filter O.D. (Inches) 3.698 in.
Fuel Filter O.D. (mm) 94 mm
Fuel Filter Style Spin-On Fuel Filter
Gasket I.D. (Inches) 3.174 in.
Gasket I.D. (mm) 80 mm
UNSPSC 40161513
Napa 3120 (used W/ 3118 Primary) Secondary Fuel
Contents 10 Micron
Fuel Filter Gasket O.D. (Inches) 3.444 in.
Fuel Filter Gasket O.D. (mm) 87 mm
Fuel Filter Gasket Thickness (Inches) .26 in.
Fuel Filter Gasket Thickness (mm) 7 mm
Fuel Filter Height (Inches) 6.93 in.
Fuel Filter Height (mm) 176 mm
Fuel Filter Inlet Thread Size (Inches) 13/16 in. - 12
Fuel Filter O.D. (Inches) 3.698 in.
Fuel Filter O.D. (mm) 94 mm
Fuel Filter Style Spin-On Fuel Filter
Gasket I.D. (Inches) 3.1 in.
Gasket I.D. (mm) 79 mm
UNSPSC 40161513
Napa 3418 (with drain valve)
Contents 12 microns
Fuel Filter Gasket O.D. (Inches) 3.444 in.
Fuel Filter Gasket O.D. (mm) 87 mm
Fuel Filter Gasket Thickness (Inches) .26 in.
Fuel Filter Gasket Thickness (mm) 7 mm
Fuel Filter Height (Inches) 8.419 in.
Fuel Filter Height (mm) 214 mm
Fuel Filter Inlet Thread Size (Inches) 1 in. - 12
Fuel Filter O.D. (Inches) 3.698 in.
Fuel Filter O.D. (mm) 94 mm
Fuel Filter Style Spin-On Fuel/Water Separator Filter
Gasket I.D. (Inches) 3.1 in.
Gasket I.D. (mm) 79 mm
UNSPSC 40161513