Some of the Mopar ECU will retard the ignition timing a little (1 to 2 degrees per 1000 RPM above 5000 RPM :scope) above 5000 RPM
when I first started paying attention to drag race tuning a lot of the faster racers had a switch to turn off one set of points to retard the ignition timing in high gear
It seems like some of the street and strip MSD boxes would also, maybe not as i never used them
ALL ignition boxes retard with RPM. All of them. The best box I’ve tested for that is a early 1980’s DC Gold Box. It retards 1 degree in 10,000 RPM. I think it took 8,000 RPM to get that.
I just tested a well know box for street stuff and it retards 6 or 7 degrees (I can’t remember if that box was 6 or 7 because I tested 5 boxes that day and that one was one of the boxes that had the most retard) and IIRC started retarding at about 4,000 or so and kept retarding to 8,000.
