You can look at what the factory used to get a good idea. Until the compression got above 11 you still saw stock style coils. There were some dual point distributors with lower compression stuff, but the coils were pretty much stock.
The Max Wedges are a good example of early high output ignitions. They used a transistorized control unit.
I would say anything with more than 170 PSI cranking pressure might show some benefit.
