I run the cam in a low compression (probably under 9) 440 in a '67 Dart automatic.
I dont have anything to compare it to but I know it's milder than the 509 (which I think is closer to 251 @ 50 than 248). Sounds nice and moves my car along pretty good according to my butt dyno.
Heres some video. Around 1:05 there is some outside video and idling.
http://www.youtube.com/watch?v=h3d-jleaRhMI think if I could do it over again, I'd buy the comp cams version of the 509 which has more exhaust duration. I could deal with a lumpier idle and driveability wouldn't suffer much especially for how often I drive it.
