just disproved my warped filter theory. i put the last filter back on and started the engine, waited for the pressure at the gauge to rise to normal (60 psi cold), and then went to inspect the filter. it pushed the oring out while i was watching. the filter wasnt hitting anything and had no signs of damage from the last time. it has to be pressure. where is the oil pressure gauge signal from? before or after the filter? is there an oil pathway that can be partially plugged that would cause pressure to rise in the filter?