I should log in more often. I'm thinking about a cam change on my 355 and a 406/407/409 I plan to build in a year or so. Your collective calculations using DCR finally got my attention. I currently run an XE274H but I want to change to a solid lifter cam. I considered this when I did a mild refresh on the short block five years ago. My DCR now is just under 8 and I'm running 72cc Dart Iron Eagle 180's w/ KB flat tops. I can run 87 octane and I can't get a ping. Makes me suspect I'm not getting enough squeeze and I might switch to thinner head gaskets. Since the heads are coming off anyway, should I just get them shaved instead? I know this is a little off the path here for this thread but it's all relative. The car is a '65 Tempest. I have a noisy 3.73 gear getting changed to a 3.55 and a 10" converter, not sure of the stall speed.