First off, the idle screw is a legacy component and not to be used on any of the 7M vehicles. If you have to adjust it to get a consistent idle then you haven't yet found the problem.
Second, have you checked for any diagnostic codes?
Third, when setting the mechanical timing did you check to make sure that the #1 piston is at TDC when the indicator on the balancer says 0?? The rubber in the balancer can twist as it ages putting the 0? mark off more than 10?.
Fourth, when setting the ignition timing, did you have the diagnostic jumper in place?
Fifth, have you tested the ISC valve (electrical and mechanical) and it's plumbing?
Sixth, I dunno what's with the counting.... Started with one and just had to go as high as I could (pathetic, I know).
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