New to the Mopar scene.. got 68' cuda need help.. new motor...

Test driving in bare feet? sigh....
The lightest springs bring the curve in way fast. great for a drag car, not the best for a street car on pump fuel. You want about 1* more total in it. Is a heavy spring limiting the centrifical advance? or is the plate? If it's the plate, I'd swap it or grind the slots a little longer. If it's the heavy spring with the oblong end, you can re-form the oblong end to get more advance out of it. I like at least 18* initial, sometimes as much as 20* if the starting system and cam/compression allow it. With a total of around 35* or so with the vaccum disconnected for testing.