the filter business is weird..... the FL910s(Essentially a Shorter Fl400s) is a 3/4-16 thread , and crosses to a fram **3614( Fram**3600), the FL820s, and FL500s have a Metric 22x1.5mm thread (Fram **2/ **10575) (btw, many jobber filters, and "smaller" filter lines have supersceeded their 820s equiv with their 500s equiv....it's the same thread,similar bypass settings, just a taller and narrower can)
but huh... the Fram Lookup shows the Base/LX Trims using the 820s equiv.(**2) and the Police Interceptor Models taking the 910s equivalent (**3614)
same with WIX. some taking the 51372 (820s), some taking the 51348 (910s) with no footnotes denoting different models, etc...
you learn something every day.....