Re: Quick question on the GM HEI dist on 258
Rotor phasing will work on all distributors that have a centrifugal advance, and most that have vacuum advance.
If the advance is controlled by your computer, the only way to phase the rotor is to move the reluctor around the shaft.
Or in the case of a GM HEI with the three screw top ring on the mag trigger, you can move the mag trigger points by simply rotating the outside ring one screw hole...
That sould be the equivlent of about 24 degrees of rotor movement... if I remember correctly