The timing on the 420 and 560 is not adjustable. I know the distributor has a slot there, but if you will notice, there is no pickup in the distributor housing to change the timing. The distributor in the application is for high voltage distribution ONLY.
The rails on the 420 and 560 are of the same composition. I don't know why they do not break as often in the 560?
1992 500E (very soon I hope
1981 280GE SWB
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