Looking at Filterbarn, if I type in PH8A or FL1A, I get a lot of options. Even though this is a common filter, Filterbarn for some reason doesn't have the Wix 51515, the Napa Gold 1515, the FL1A, or the Purolator L30001 listed. They do, however suggest the Napa 1521 and the Fram PH3651A as crossing to these numbers. It looks like the 1521 would fit, but it's a lot shorter than the 1515. Napa doesn't list it as an equivalent for the FL1A. The PH3651A apparently crosses to the Napa 1521.
Then it gets more interesting. According to Napa, there is a two-quart version of the 1515, the 1773, which it looks like would fit my truck, but I'm not sure if it's just longer with the same filtering element or what. Filterbarn does for some reason have the 1773, and for $3.11, which seems pretty cheap.
By this time you're thinking, "Hey, why does this matter? Just buy an FL1A and be done with it!." You're probably right, but if folks wanted to just leave well enough alone, why would this board exist?
Then it gets more interesting. According to Napa, there is a two-quart version of the 1515, the 1773, which it looks like would fit my truck, but I'm not sure if it's just longer with the same filtering element or what. Filterbarn does for some reason have the 1773, and for $3.11, which seems pretty cheap.
By this time you're thinking, "Hey, why does this matter? Just buy an FL1A and be done with it!." You're probably right, but if folks wanted to just leave well enough alone, why would this board exist?