Originally Posted by chubbie
Ok also the fl-1a has a larger diamater so if the backing plate that it's screwing on to has to be wide enough for it. I see.
The threads are the same, it just has to fit. For instance, on the Cherokee in my sig, the factory filter is a short Fram PH16 size, but the PH3600/FL400S fits, as does the FL1A/PH8A size. Just make sure there's enough room around them. On your Valvoline Ecore ADBV, that's a common flaw with black nitrile ADBVs, especially on Purolator made filters-engine heat stiffens them & they quit sealing-I've had Quaker State filter ADBVs quit inside of 2000 miles before!