so from what i'm seeing its a gm based system, wonder if a scan tool would tell you any data? the timing sounds correct. I'm still leaning towards a leaking injector might not be a bad leak, can you look in the throttle body and see what the spray patterns like when its at idle? Does this motor have adjustable rockers? I'm not knowledgeable about these older fords, but i know Ford did use them at one time.