Is it normal for a 4.9L inline 6 MT to run this bad?

No, I have a OBD1 scanner but the check engine light never comes on. Can there be codes stored without the check engine light comming on? Since the OBD port is under the hood I don't know of an easy way to plug in the scanner and have it availble while driving. The ignition timing has been check, rechecked and then checked again after a rebuilt distributor was installed as a failed attempt to fix the problem It was not a bad EGR valve either. With the low milage I can't imagine the timing chain could be wrong or jumped. I don't know if this engine can ever run right or it it needs to be scrapped for a V8. I would love to hear feedback from a Ford truck owner with a similar MT model. Thanks for writing back