The HEI distributor is not likely to work - the SYNC sensor won't be there, and the stator/reluctor assembly is probably incompatible with the RENIX system (that's just a guess, tho; and I could certainly be wrong!)
If it's not advancing, it's probably not requiring indexing (that's where you cut the tab, engage the gears as close to "right" as possible, and fine-tune with the movement of the distributor housing.) Failure to advance would be more of a problem with the system not sensing engine speed properly - could be a CPS starting to go West on you, could be a beginning failure of the ICM (which, as I recall, generates the TACH signal for the IP.)
As a check for the latter - does your Tach read anywhere close to actual speed? Have you had it verified? You should be able to use a "non-contact tachometer" on the HD to take a direct reading, and then compare it to the tach. If it's too far off, I'd probably start by changing the ICM assembly - if it's close, start with the CPS (since it generates the base timing signal for both ignition and fuel injection.)
How would i go about having the Tach verified? It has a new CPS sensor on it already, that was one of the first things i replaced. I will cut the tab off tomorrow and see if that helps at all.