Have a look in the vintage section, someone recently went through this.

As for penetrant, don't use WD-40 , it is a miserable lubricant. I use " Blaster " brand with good results.

The problem is corrosion between an aluminum distributor body and a steel adapter pretty much locks the two together leaving penetrating oil nowhere to go. ( There are cars with steel distributors / aluminum adapter ) If your distributor is steel and adapter aluminum, heating ( warming ) the aluminum can help.

In the vintage thread, the aluminum adapter was easily removable. This could be helpful as you can heat things away from the car.

A key points are: If you get any movement, stop then turn the other way. The goal is to work with the movement you have rather than forcing it past where it stops as this can jam things even worse. Initial movement will be very small and as you work things back and forth the movement will increase.

Don't hammer things apart, this can break casting.




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