There is the normal type identified by normal type cap, spark plug and plug cables and the radio supressed type with special cap, spark plug and plug cables similar to the M-type vehicles.
The Pertronix kit for the normal type is easily available (#2863N24). For the radio supressed type I dont know.
This is an email I wrote to pertronix some years ago:
Hello, I have a Volvo 1976 C303 with Bosch distributor # 0 231 305 058. Its a 24 volt system. Will the 2863N24 work for this distributor? And can any of your flamethrower coils be used together with the Ignitor on a 24 volt system? Thanks in advance. ------------ Yes, the 2863N24 will work in your distributor. Use coil #40511 and a 3.0 ohm ballast resistor. Carl Alcocer Pertonix Inc. 909-273-6007
And yes, it did work. Hope this helps.
Edit: Link to old thread.