I apologize for all the confusion. I am still trying to figure it out. I have actual test data with calibrated gauges. If the Ford FL-HP has a 27 micron rating or lower in my opinion it is the best filter. If it has a 60 micron rating it is a poor choice for a street engine. The differential pressure I registered across it was fantastic, I am guaranteed never to bypass and if for some strange reason it did it bypasses on the clean side of the filter!!!!
This link
http://minimopar.knizefamily.net/oilfilters/index.html has some dated material, on the motorcraft which he compares as a puralator he indicateds a dome side bypass or in other words dirty side, this is not true, I know for a fact it is a clean side.
I need to install a FL-1A filter and check the differential across it. If it is less than 10 psig after the engine is warm it is my filter of choice since the bypass opens at 11 psig. Even if it is more than 10 psig with engine cold I dont care, let it bypass, it is a CLEAN SIDE BYPASS. I also know the micron rating is 25.
If in fact any of us can find what the micron rating for the FL-1HP and it is less than 30 micron, another great choice.
As far as asking the engine builder, forget it, they know less than we all do at this point and to be honest if your engine is good shape anything will work.
I quit drinking got off on a tanget and now trying to get to the bottom of it.