[scooder]

I love the way we, me included, refer to an ignition with vacuum and centrifugal advance as modern, it makes me all happy inside, knowing that although we may not sing from the same hymn sheet, it is in the same book. And it's an old book.
With the chaps who like a tickle more advance in their ignition. I feel there is good reason for this.
The better gas we have now, higher octane, will stand a bit more advance early on. For max power the stock Ford figure still stands though.
So what's really needed is to get the advance in earlier. This would give you that "I like a bit of extra advance" seat of the pants feel. It would also have the extra advance in relatively low engine speed cruise. So this fits even with the cruise at 2000-2500 rpm gang. But keep the max timing stock.
A recurve of this nature can make the engine come alive, feels like a bunch more horses under the hood, even though the power is actually the same max, it just delivers it better. On a heavy car you have to be a bit more conservative with your all in rpm level.
This is why I like to fit the lightest springs from the recurve kits I can in a converted chevy ignition, I'd like them lighter, next one I will probably wind my own springs. Start changing other stuff and the ignition curve will want to be different again.
As I stated earlier, I set a stocker at stock timing and be done with it, this allows the car to be driven hard with no issues and operates as it should. If it's modified, it gets what it needs.
And if it's got one of those modern Mallory things hung off it, just getting it to run as good as a stock ignition is a ball ache. But they are recurveable, still wish they had lighter springs in the kit.
Sorry for waffle,
Martin.