For a supercharged 5.0, who makes the best ignition with timing retard. I have looked at the Crane HI6R-TRC and the MSD 6BTM. I don't know anything about them except what I see in ads. I see Crane promotes their digital technology over the MSD's analog and claims 3 times the spark energy. I like the msd's numbered retard dial with the 1,2, or 3 vs the crane just goes from 0 to 20 degrees, whether that matters or not. What are you guys using with good luck. I want something good and reliable also. Thanks for any advise.