129" Power Package Engine Performance Kit — Bore 4.320", Stroke 4.375", Black

S&S CYCLE 129" Power Package Engine Performance Kit — Bore 4.320", Stroke 4.375", Black – 18-24 Softail, 17-23 Touring

S&S CYCLE
0904-0106
310-1226
Converts a 107" oil‑cooled M8 to 129" without case machining. Big-bore cylinders, matched cam and pump, MLS head gaskets. Made in USA.
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€2,928.22
€3,681.19
Save €752.97
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  Delivery policy

In stock items will be shipped within 1-3 days.

  Return policy

You can return the products within 14 days for a full refund, check our returns policy.

The 129" Power Package Engine Performance Kit transforms a 107" oil-cooled M8 into a 129" powerplant without case machining. 🚀🇺🇸

Designed for straightforward installation and reliable service, the kit delivers big-bore cylinders with matching cam, cam plate and oil pump for improved torque and durability.

  • Independent scavenge sections for the flywheel cavity and cam chest
  • Magnet in the cam chest to reduce debris entering the oil pump
  • Debris screens in both scavenge pickups and removable passage plugs for easy servicing
  • High-performance conical single-wire valve springs and MLS head gaskets for reliable sealing
  • Performance-matched 550 cam and supplied cam plate for optimized timing
  • Retains original engine serial numbers and works with the stock crankcase
  • No case machining required; engineered for serviceability
  • Made in the USA

Every component is engineered to provide consistent, race-ready performance while remaining serviceable for routine maintenance and rebuilds.

: 0904-0106
In Stock

Data sheet

Type
Engine
Units
Kit
Color/Finish
Black, Non-Highlighted Fins
Base Color
Black
Style
Big Bore
Brand
S&S CYCLE
Bore Size
4,320"
Displacement
129"
Cooling System
Oil Cooled
Stroke Length
4,375"
Cam Drive Type
Chain
Harley Family
Softail
Touring

Shipping Policy

Shipping Areas:

We ship to:

  • Spain (Peninsula and Balearic Islands)
  • European Union countries

We do not ship to the Canary Islands, Ceuta, or Melilla.

Shipping Times:

  • Spain (Peninsula): 2–4 business days
  • Balearic Islands: 3–5 business days
  • EU countries: 3–7 business days depending on destination

Shipping Costs:

Shipping costs are calculated automatically at checkout based on destination and weight.

Free shipping may be offered for qualifying orders, as specified on our website.

Order Processing:

Orders are processed within 1–2 business days after payment confirmation. Orders placed on weekends or public holidays are processed the next business day.

Delivery Issues:

If your order is delayed or arrives damaged, you must notify us within 14 calendar days. We will investigate the issue and offer a resolution in accordance with applicable consumer protection laws.

Return & Withdrawal Policy

Right of Withdrawal:

In accordance with Royal Legislative Decree 1/2007 (Ley de Defensa de los Consumidores y Usuarios), you have the right to withdraw from your purchase within 14 calendar days from the date of receipt, without giving any reason.

To exercise this right, contact us via email or through our website, providing your order number and contact details.

Return Conditions:

  • Products must be unused, in original condition and packaging.
  • Return shipping costs are the responsibility of the customer, unless the product is defective or sent in error.
  • Refunds will be issued within 14 days of receiving the returned goods.

Items Excluded from Return:

  • Custom or personalized products
  • Sealed items that were unsealed after delivery and are unsuitable for return due to hygiene (e.g. cosmetics, personal care)
  • Digital content delivered electronically once download or streaming has begun

If you want to return an item, please contact us first to give you detailed instructions.

This product fits the following vehicles. Use the filters below to narrow down the list if needed.

Manufacturer Model Family Year Notes
Harley Davidson Softail Deluxe 107 Softail 2018 O/C (107")
Harley Davidson Softail Deluxe 107 Softail 2019 O/C (107")
Harley Davidson Softail Deluxe 107 Softail 2020 O/C (107")
Harley Davidson Softail Fat Boy 107 Softail 2018 O/C (107")
Harley Davidson Softail Fat Boy 107 Softail 2019 O/C (107")
Harley Davidson Softail Fat Boy 107 Softail 2020 O/C (107")
Harley Davidson Softail Heritage Classic 107 Softail 2018 O/C (107")
Harley Davidson Softail Heritage Classic 107 Softail 2019 O/C (107")
Harley Davidson Softail Heritage Classic 107 Softail 2020 O/C (107")
Harley Davidson Softail Heritage Classic 107 Softail 2021 O/C (107")
Harley Davidson Softail Heritage Classic 107 Softail 2022 O/C (107")
Harley Davidson Road King 107 Touring 2017 O/C (107")
Harley Davidson Road King 107 Touring 2018 O/C (107")
Harley Davidson Road King 107 Touring 2019 O/C (107")
Harley Davidson Road King 107 Touring 2017 O/C (107")
Harley Davidson Road King 107 Touring 2018 O/C (107")
Harley Davidson Road King 107 Touring 2019 O/C (107")
Harley Davidson Road King 107 Touring 2020 O/C (107")
Harley Davidson Road King 107 Touring 2021 O/C (107")
Harley Davidson Road King 107 Touring 2022 O/C (107")
Harley Davidson Road King Classic 107 Touring 2017 O/C (107")
Harley Davidson Road King Classic 107 Touring 2018 O/C (107")
Harley Davidson Road King Classic 107 Touring 2019 O/C (107")
Harley Davidson Road King Special 107 Touring 2017 O/C (107")
Harley Davidson Road King Special 107 Touring 2018 O/C (107")
Harley Davidson Electra Glide Standard 107 Touring 2019 O/C (107")
Harley Davidson Electra Glide Standard 107 Touring 2020 O/C (107")
Harley Davidson Electra Glide Standard 107 Touring 2021 O/C (107")
Harley Davidson Electra Glide Standard 107 Touring 2022 O/C (107")
Harley Davidson Electra Glide Ultra Classic 107 Touring 2019 O/C (107")
Harley Davidson Street Glide 107 Touring 2017 O/C (107")
Harley Davidson Street Glide 107 Touring 2018 O/C (107")
Harley Davidson Street Glide 107 Touring 2019 O/C (107")
Harley Davidson Street Glide 107 Touring 2017 O/C (107")
Harley Davidson Street Glide Anniversary 107 Touring 2018 O/C (107")
Harley Davidson Street Glide 107 Touring 2019 O/C (107")
Harley Davidson Street Glide 107 Touring 2020 O/C (107")
Harley Davidson Street Glide 107 Touring 2021 O/C (107")
Harley Davidson Street Glide 107 Touring 2022 O/C (107")
Harley Davidson Street Glide 107 Touring 2023 O/C (107")
Harley Davidson Street Glide Special 107 Touring 2017 O/C (107")
Harley Davidson Street Glide Special 107 Touring 2018 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2018 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2019 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2020 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2021 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2022 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2023 O/C (107")
Harley Davidson Softail Sport Glide 107 Softail 2024 O/C (107")
Harley Davidson Softail Slim 107 Softail 2018 O/C (107")
Harley Davidson Softail Slim 107 Softail 2019 O/C (107")
Harley Davidson Softail Slim 107 Softail 2020 O/C (107")
Harley Davidson Softail Slim 107 Softail 2021 O/C (107")
Harley Davidson Road Glide 107 Touring 2017 O/C (107")
Harley Davidson Road Glide 107 Touring 2018 O/C (107")
Harley Davidson Road Glide 107 Touring 2019 O/C (107")
Harley Davidson Road Glide 107 Touring 2017 O/C (107")
Harley Davidson Road Glide 107 Touring 2018 O/C (107")
Harley Davidson Road Glide 107 Touring 2019 O/C (107")
Harley Davidson Road Glide 107 Touring 2020 O/C (107")
Harley Davidson Road Glide 107 Touring 2021 O/C (107")
Harley Davidson Road Glide 107 Touring 2022 O/C (107")
Harley Davidson Road Glide 107 Touring 2023 O/C (107")
Harley Davidson Road Glide Special 107 Touring 2017 O/C (107")
Harley Davidson Road Glide Special 107 Touring 2018 O/C (107")
Harley Davidson Softail Street Bob 107 Softail 2018 O/C (107")
Harley Davidson Softail Street Bob 107 Softail 2019 O/C (107")
Harley Davidson Softail Street Bob 107 Softail 2020 O/C (107")
Harley Davidson Softail Breakout 107 Softail 2018 O/C (107")
Harley Davidson Softail Breakout 107 Softail 2019 O/C (107")
Harley Davidson Softail Breakout 107 Softail 2020 O/C (107")
Harley Davidson Softail Fat Bob 107 Softail 2018 O/C (107")
Harley Davidson Softail Fat Bob 107 Softail 2019 O/C (107")
Harley Davidson Softail Fat Bob 107 Softail 2021 O/C (107")
Harley Davidson Softail Low Rider 107 Softail 2018 O/C (107")
Harley Davidson Softail Low Rider 107 Softail 2019 O/C (107")
Harley Davidson Softail Low Rider 107 Softail 2020 O/C (107")
Harley Davidson Softail Standard Softail 2021 O/C (107")
Harley Davidson Softail Standard Softail 2020 O/C (107")
Harley Davidson Softail Standard Softail 2021 O/C (107")
Harley Davidson Softail Standard Softail 2022 O/C (107")
Harley Davidson Softail Standard Softail 2023 O/C (107")
Harley Davidson Softail Standard Softail 2024 O/C (107")