5.The MSD 6LS ignition controller is more than just a spark box. It offers several programmable features to control timing and rpm adjustments. Using the supplied Pro Data software, you can program a custom timing advance map, two different rev limiters for starting line holeshots and peak rpm, and a step-retard to remove up to 15 degrees of timing at a specific time. This is an ideal feature when running nitrous oxide. The 6LS also has the capability to constantly alter the ignition timing at idle to help smooth out a rough idle if you so desire. And if you're not into playing with computers, MSD supplies six preprogrammed timing advance curves that are stored in plug-in modules. The Edelbrock intake has mounting lugs for the 6LS at the front of the intake.