Cap-A-Dapt Kit Adjustable Rotor
InfoVehicle Info Needed
MSD IGNITIONPART NUMBER: 121-8420MSD

Cap-A-Dapt Kit Adjustable Rotor

$12145$134.95You Save$13.50
1 left in stock
ShippingShips Today
Lowest PriceLowest Price Guarantee

Cap-A-Dapts
Cap-A-Dapt Kit
  • Adjustable Rotor
  • For Chevy V8

    MSD Cap-A-Dapt adapts a large Ford-style cap onto most MSD Billet and Pro-Billet Distributors & spaces the spark plug terminals farther apart which lessens the chance of crossfire and ionization occurring. Spark plug-type terminals provide tight connections that will not vibrate loose. Rotors are injection molded out of Rynite for incredible strength and resistance to spark. Incorporated thick vanes stir air even more for additional ionization prevention. The adjustable two piece rotor allows you to adjust the rotor to to the cap terminal alignment so you can adjust the rotor phasing. If you are running a Multi-Step Retard or Timing Controller the ability to adjust the rotor phasing is beneficial. Cap-A-Dapts also include a cap spacer.

    Kit Includes:

    • High-Quality Cap with Brass Terminals
    • Rotor
    • Cap Spacer
    • MSD distributor caps and rotors are designed with performance in mind and molded from high-quality, voltage-insulating material with terminals that resist carbon tracking. Whenever the distributor cap is changed, you should install a new rotor. Likewise, if you're replacing the rotor, be sure to install a new cap as well. MSD has new kits featuring Rynite injection molded distributor caps and retainers to complete your distributor tune-up. MSD also has Cap-A-Dapts to fit large Ford-style caps onto MSD distributors.
      Show More

      Keep your ignition system running at peak performance with MSD Distributor Caps and Rotors, engineered for long-lasting reliability and superior spark delivery. Whether you're performing routine maintenance or upgrading your ignition components, these high-quality parts are designed to meet the demands of street and strip applications alike.

      Each MSD distributor cap and rotor is built with performance in mind, using high-dielectric strength materials that resist carbon tracking and ensure accurate spark distribution. The brass terminals provide better conductivity and longer life compared to standard aluminum terminals, helping to deliver consistent ignition timing and improved throttle response.

      Designed to be a direct-fit replacement for MSD distributors, the MSD distributor cap ensures a secure connection and excellent durability under high-heat, high-vibration engine bay conditions. Whether you're tackling tough driving conditions or logging laps at the track, you can count on these components to perform when it matters most.

      The MSD rotor is equally robust, constructed from top-grade materials to handle the high voltage output of performance ignition systems. It delivers precise spark transfer to the cap terminals, supporting high-RPM operation and clean combustion with every cycle.

      For street cars, muscle cars, and race vehicles alike, MSD Distributor Caps and Rotors are the smart choice for drivers who demand dependability, performance, and easy installation. Upgrade with MSD to maintain your ignition system’s edge and keep your engine firing on all cylinders.

    Part TypeDistributor Cap and Rotor Kit
    Product LineMSD Distributor Caps and Rotors
    BrandMSD IGNITION
    Package Height5.5
    Package Width5.6
    Package Length6.2
    Weight1.48 PG
    Part CategoryPerformance Parts
    Part FitmentSemi Universal
    Vendor Part Number8420MSD
    Package Qty1
    Package TypeEA
    No Questions
    No Reviews

    Items You Need

    Spark Plug Wire Separators Black

    JEGS

    Spark Plug Wire Separators Black

    Part Number : 555-40320
    $2039$22.99
    You Save$2.60
    Distributor Boot and Terminal Kit HEI Cap Terminal

    JEGS

    Distributor Boot and Terminal Kit HEI Cap Terminal

    Part Number : 555-40331
    $499$5.39
    You Save$0.40
    Snap On Spark Plug Wire Markers Fits: (spark plug wires) 7mm to 8mm

    JEGS

    Snap On Spark Plug Wire Markers Fits: (spark plug wires) 7mm to 8mm

    Part Number : 555-40350
    $739$8.09
    You Save$0.70
    Snap On Spark Plug Wire Markers Fits: (spark plug wires) 8.5mm to 9mm

    JEGS

    Snap On Spark Plug Wire Markers Fits: (spark plug wires) 8.5mm to 9mm

    Part Number : 555-40351
    $739$8.09
    You Save$0.70
    Spark Plug Wire Separator Kit Black

    JEGS

    Spark Plug Wire Separator Kit Black

    Part Number : 555-40360
    $399$4.29
    You Save$0.30
    Competition Spark Plug Wire Loom Kit Black

    JEGS

    Competition Spark Plug Wire Loom Kit Black

    Part Number : 555-40370
    $1299$14.59
    You Save$1.60
    Self-Powered Timing Light [Powered by (2) D-Cell Batteries]

    JEGS

    Self-Powered Timing Light [Powered by (2) D-Cell Batteries]

    Part Number : 555-W80578
    $4799$52.99
    You Save$5.00
    Replacement Boots and Terminals 90° HEI

    MSD IGNITION

    Replacement Boots and Terminals 90° HEI

    Part Number : 121-3320
    $1350$15.00
    You Save$1.50
    Distributor Cap Ford Style

    MSD IGNITION

    Distributor Cap Ford Style

    Part Number : 121-8408
    $5522$61.35
    You Save$6.13
    Cap-A-Dapt Rotor Adjustable

    MSD IGNITION

    Cap-A-Dapt Rotor Adjustable

    Part Number : 121-8421
    $6317$70.19
    You Save$7.02
    Cap-A-Dapt Cap Spacer For Large Caps & Fords

    MSD IGNITION

    Cap-A-Dapt Cap Spacer For Large Caps & Fords

    Part Number : 121-8446
    $3746$41.62
    You Save$4.16
    Spark Guard Dielectric Grease Resealable Container

    MSD IGNITION

    Spark Guard Dielectric Grease Resealable Container

    Part Number : 121-8804
    $4159$46.21
    You Save$4.62
    Pro Clamp Wire Separators Includes: (2) 4-Wire Assemblies

    MSD IGNITION

    Pro Clamp Wire Separators Includes: (2) 4-Wire Assemblies

    Part Number : 121-8843
    $3746$41.62
    You Save$4.16
    Replacement Boots and Terminals 90° MSD Logo

    MSD IGNITION

    Replacement Boots and Terminals 90° MSD Logo

    Part Number : 121-8850
    $4008$44.53
    You Save$4.45
    Timing Tape Sheet Includes (8) Different Tapes

    MSD IGNITION

    Timing Tape Sheet Includes (8) Different Tapes

    Part Number : 121-8985
    $795$8.83
    You Save$0.88
    Some parts are not legal for use in California or other states with similar laws / regulations
    p65 warning
    Your Cart

    Your shopping cart is empty!