What Fram (Allied Signal) has to say about filter bypass..

[marrone@wco.com (Frank Marrone)]

It wasn't easy but I finally found a phone number on the WEB for
Fram/Allied Signal Automotive (800 810 4340).  Jim Trombly of Allied
confirms that the PH8A has a filter bypass with an activation pressure
of 8-10 PSI. 

I'd say that about settles it although I have a feeling that there are
some out there who are still willing to refute this.

Have a nice day.
Frank Marrone          MK I Tiger B9471116
marrone@wco.com        1966 LTD 
                       Series I Alpine  (2.3L powered by Ford)
                       Yamaha Seca 900