I got a spring kit and messed around until I think I have a decent curve, or not I don't know. I was getting some pre ignition at the 2000-2500 rpm range under full throttle in my 440 because all my timing was coming in at 2000 rpm. soooo I played with springs until I now have 11 at idle,15 at 1500, 25 at 2000 and all in at 36 at 2500. BUT to get this I have to use the vac advance which I just read doesn't count in the total timing? that doesn't make sense? my vac isn't doing anything until about 2200 then it helps up to the 36 at 2500. I know this is a screwed up question the way I discribe it but I can't go test drive the car because the roads are a mess for a few more months, anyone care to tell me if I'm probably ok or if I need to change anything?