MSD Ignition Timing/Rev Control Features: Runs Carb LS1/6 Eng w/out Complicated EFI Hardware Program 2-Step Rev Limiter; Vac Adv; Step Retard Direct Plug-In Factory Components Map Timing Curve Using Pro-Data Software Easy Installation; Few Connections Are Required Programmable Via a PC Height: 4.00" Width: 10.00" Length: 6.00" Weight: 4.00 lbs