Had a problem. My old Jacobs Pro Street system cd was malfunctioning, so what to do, what to do? One trusted advisor told me nothing short of an MSD 7AL3 would clean up my big cam on the 427. Wolflplace said his dyno has a 6AL and it was keeping up just fine, thank you. Called a 7 second racer down the street from me (well, in the country that's 5 miles), and he said to do what he did, for the money buy a Mallory V1 digital #685, and for $236 that's just what I did. Multi-strike, 2 rev limiters, window switch, lots of energy, and who knows what else for that kind of money just stroked my wallet the right way. Hell, I don't even know how a window switch works, but I'm excited.