Yes you can run a dual pickup dizzy Mr Dedman and myself are running one in our slant turbo valiants . I believe most were found in the lean burn era mid 70's. You can run a Hobbs switch of some sort to switch between the two pickups. Ideally a dual set of contact switch that under vacuum one pickup is live and under boost the other on retards your timing.
The member on. Org who I bought my dizzy from told me there's about a 8° difference between the two pickups.
I never hooked mine up this way because I like the 6530 because it has different rev limits plus timing control and data logging....