Need To Know

Ineligible for Return

Contains items that cannot be returned


This is garage sale priced because the product packaging was damaged/torn when we received it. There is no visible damage to this distributor and all parts are retained for proper install. Product is new, but will be packaged in plain brown box. It is being sold as is pictured. Please see photos above for further details.



You can't go wrong with the best selling MSD Billet Distributor! The housing is machined from a billet of 6061-T6 aluminum on a state-of-the-art CNC machine producing exact tolerances. For high rpm stability, a .500” steel shaft is supported by a sealed ball bearing and a long sintered bushing. This shaft also receives a QPQ coating for friction reduction and resistance to corrosion. A precision machined reluctor is attached to the shaft which triggers the magnetic pick-up mounted in the housing. This high output magnetic pick-up is the most accurate way to trigger your ignition. Plus, with no moving parts to wear or adjust, the pick-up is maintenance free! Just above the pick-up is MSD’s adjustable mechanical advance assembly. Different springs and stop bushings are supplied so you can tune an advance curve to match your application.

Fits Small Block or Big Block Chevy V8.

Instruction Sheet for 547-5551 (pdf) 



  1. Must be used with a CD Ignition Control (MSD 6, 7, 8 or 10 Series).
  2. Will not accept a vacuum advance canister.
  • CNC machined billet aluminum housing and billet aluminum base
  • Easy-to-adjust mechanical advance with supplied springs and stop bushings
  • Maintenance-free magnetic pickup and precision reluctor create stable trigger signals throughout the RPM range
  • Polished steel shaft is QPQ coated and guided by a sealed ball bearing and extra long sintered bushing
  • Advance plate and weights are fine blanked from Chromoly steel and QPQ coated for friction reduction
  • Mechanical advance assembly can be locked out for crank trigger systems
  • Advance weight pins are staked and tig welded to the plate
  • Nylon pads ensure smooth operation of the advance weights
  • Special oil tract improves lubrication to the distributor and cam gear
  • O-ring seals can be added to modified blocks to improve oil pressure control
  • Supplied with an HEI style distributor cap and rotor (accepts MSD Cap-A-Dapts)