Your new filter will come with a new o-ring, either by itself or installed on the cap if so equipped. Make sure its right side up. IE the flat side of the oring goes DOWN on the fuel bowl. And make sure the cap touches the bowl itself, or you will have no leaking at idle, but lots of leaking at throttle.

No need to replace the fuel heater unless it blows fuses. Then just unplug it. It will run fine without the heater until you can get a new heater element. Then get it from International. Part # 1821196C92. like 30 bux. FORD wants 150 bux for the same part.

CPS had nothing to do with cold cranking, and EVERYTHING to do with the engine running period.

Oh yea, welcome aboard!