So all the other damage was done taking it off? On the forward side of the filter where the hard line from the lift pump enters the filter, there is a T fitting. Hook up a 100PSI gauge there and check the base fuel pressure there. You may have a regulator issue or clogged return path to the tank. Should have 10 PSI when cranking, 20 PSI at idle ramping up to 60PSI by peak torque RPM(1400-1500RPM). Not sure how much pressure the lift pump is capable of generating, but too much is probably not too good for a sheetmetal skinned fuel filter…
I show how to hook up one in this video…