Seems to my they only recommended changing the filter every other time you changed oil.
that's what i do with my dump. on my gmc's the 228 didnt have one and it still runs fine.
this is what it looked like before i cleaned it
http://s1301.photobucket.com/user/B...amp;_suid=137165827225807111468686288676and cleaned
http://s1301.photobucket.com/user/B...amp;_suid=137165827225807111468686288676 on the 270's that i put in the 40 and the ashton i did in this manner.
http://s1301.photobucket.com/user/B...mp;_suid=1371657430976011316549222269273i know some that still even run the bypass filter inaddition to the full flow conversion.
others use filters with internal relief valves like the one you described
just curious what is the differential pressure to cause the relief to open
