I suspect I have a defective Filter. Cycling between full Flow and Bypass. I will change filter Monday. I have checked Tube and Seal. Not the Problem.

  

What brand filter are you using? A lot of defects out there now even the big names.

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All fixed  up. Changed the Filter and that has restored Pressure to 55-60 cold Idle which is very good pressure I think for a fresh Engine.

  

What brand was the bad filter and what brand did yiu go with

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Glad you found the problem being with the oil filter.  While I have had experience with oil filters failing, it typically results in a decrease or loss of oil pressure and not where the engine experiences an erratic or a swing in the oil pressure.  My three oil filters of choice are Motorcraft, Purolator, and Wix which does alleviate any oil filter issues on my end.  Like Paul, I too am curious as to what brand of oil filter you had the problem with.

Lorena, Texas (South of Waco)

Old Ford CFL-1. Discontinued. Used it because only need for short Time before changing Oil. Using Purolator now.

  

Finally figured out problem with Oil Pressure. Stewart Warner Oil Pressure Gauge was the Problem. Got a new One to replace it and now getting constant 55-65 PSI while driving. 30 PSI at Idle. Little disappointed in Stewart Warner Gauge. 2 Years Warranty for a pricey Gauge. Live and learn t least I figured out  My Problem.