msd 2 step | JEGS Results for "msd 2 step" Showing 10 Items. Sort By: Items Per Page: MSD Ignition 2-Step Launch Controller GM LS MSD Ignition 8733 Part Number: 121-8733. MSD Ignition 8733 MSD Ignition 2-Step Launch Controller GM LS $253 (8) Ships Today FREE Shipping Lowest Price Guarantee. 2-Step Launch Controller Problems with new MSD 6al Digital and 2 step?? | NastyZ28 Jul 04, 2011my MSD box is a new style part # 6425. There is only one rev limiter built in, so the 2 step is optional when ordering it. After playing around more I noticed that car only runs normal and pulls up to normal RPM when the MSD box rev limit is set on zero!!!