1965 Ford 4400 3 cylinder diesel. This story started when I replaced the fuel tank due to the bottom of the original tank springing several leaks all at once. New aftermarket tank installed plus new tank petcock/shut off valve. Noticed a flexible automotive looking line from old tank valve to fuel filter housing was crumbling so replace with new fuel line. Noticed hose barb on dual fuel filter housing was not straight, removed it and found a previous owner had installed a hose barb with pipe threads instead of tubing threads. I found a used single fuel filter housing in a salvage yard. Any reason I need the dual filters? Now I have mounted the single and got it plumbed up. The outlet from the fuel filter is connected to the side of the simms injection pump, while the other line from the rear end top of the injection pump goes back to the filter housing. I suppose that one is for excess to recirculate correct?? I used the filter housing bleed valve and cranked the engine some, but no start. I guess I will need to have the wife crank while I open the bleed valve on the side of the pump, then when air bubbles are purged, loosen injector lines. All this purging done with fuel shut off pulled out correct?? Seems there would be a better way to purge the air without so much cranking. Could someone confirm the points with 2 question marks. Thanks for the help. By the way, the old tractor has never hesitated to start right up since I have had it for about 5 years now.