Purolator recently added the filter specs on their website. The nice thing about the Wix site is they include a spec I have not seen on other filter sites--the gasket dimensions. This was helpful for me as I am seriously considering putting a FL1A on my wife's 3.0 Aerostar, which is supposed to take the FL400S (both Motorcraft numbers). The threads are the same, bypass pressure is similar (actually more variation between brands of the spec filter than between the filter types), but the gasket is slightly different size. However, I believe the gasket mating flange on the engine is the same as for my F150 that takes the FL1A. I will measure it to be sure. But likely I will be running the bigger FL1A on the Aerostar.
[ February 08, 2004, 12:48 AM: Message edited by: TallPaul ]