Im going to be getting a 123 dizzy from Big Al at Volksbolts. Im not 100% sure which one to go for. A straight replacement for my vac advance dizzy or fully mech for when i convert to twin carbs. Ive probably misunderstood but ive been told that i can run the vac advance without connecting it to the carb and run it as a mech advance. Is there something really special about these 123 dizzys that makes this possible? What do you guys think?
Get the vacuum one, then you're covered for both cases. If you leave the vacuum transducer on the 123 disconnected, it won't add any vacuum advance, so that's fine. If one of your twin carbs has a (ported) vacuum port, you can connect that to the dissy. If not, just leave it. Easy.