The Bosch distributor for electronic ignition whether it is variant with vac advance or without can be rebuilt/refurbd and have a small but powerful trigger unit (c20mmx 30mm x 10mm) attached to the body of the unit at the point where the wires from the pickup unit exit. Following recommendations on here (and elsewhere) I approached H&H Ignition services for advice. I had my distributor rebuilt with trigger unit attached (to replace original control unit - Bosch black box) and supplied with new powerful 12V (non ballast resistor) coil. Total cost was about £140 which I though was vgvfm.
Hi - pardon my ignorance, but what did you need to send to the H&H Ignition people for them to do the work? Is this their website or have I got the wrong people?
http://www.h-h-ignitionsolutions.co.uk/Yes these are the chaps - very good, but very busy!
I sent the whole of my ignition system in a box for them to check over - leads, coil, dizzy and black box. Nothing was found to be faulty but, in order to get strongest spark they suggested dizzy was rebuilt with an integral trigger/amplifier unit to replace bosch black box + a new straight 12V coil (in place of ballasted Bosch unit)