How do I confirm pilotpart265488 fits my machine?

Compare the OEM or reference part number, machine model, engine model, and serial number. You can also submit a fitment inquiry before ordering.

In Stock

1 Set Piston Skirt 3966721 for Cummins Engine 6CT ISC ISL QSL 6L in USA

For Cummins Piston

Piston 3966721 for Cummins

OEM / REF: 3966721SKU: pilotpart265488

1 Set Piston Skirt 3966721 for Cummins Engine 6CT ISC ISL QSL 6L in USA is a Piston replacement part indexed for Part Number and Cummins Engine 6CT ISC ISL QSL 6L, with 3 application records on file. Match OEM part number 3966721 and confirm fitment for Cummins Engine Spare Parts before ordering.

Stock: In stock
Condition: New
Fitment: Cummins Engine Spare Parts
Category: Piston

Fitment support before you order
Worldwide delivery options

In stock — ready to order

$267.34USD/EA

~~$52,599.00~~Save 99%

Estimated delivery by quantity

Estimated delivery windows
Qty	Estimated delivery
1	Oct 23 – Oct 30
10	Oct 21 – Oct 28
50	Oct 19 – Oct 26

Estimates from today; confirm exact lead time before payment.

Quantity

Buy online now or add to your quote list for bulk pricing and fitment confirmation.

Confirm fitment before ordering →

Lead times can vary by freight route and customs. Contact support for expedited shipping.

Piston Description

This Piston is indexed for Part Number; Cummins Engine 6CT ISC ISL QSL 6L; Cummins s:CUMMINS Content: Piston: 1 set Piston Ring:1 set Piston Pin:1 set Piston Snap:1 set. Compare reference number 3966721 against the label on your existing Cummins component before ordering.

Before checkout, compare OEM part number 3966721, connector layout, mounting position, and machine serial number. For high-value or fitment-sensitive parts, submit the fitment form below so support can verify the match.

Part Numbers and Cross References

3966721

Applications

Part Number
Cummins Engine 6CT ISC ISL QSL 6L
Cummins s:CUMMINS Content: Piston: 1 set Piston Ring:1 set Piston Pin:1 set Piston Snap:1 set

Specifications

Part Number	3966721

Fitment Notes

Brand or application signal: Cummins Engine Spare Parts
Product family: Piston
System category: Engine Spare Parts > Cylinder Components > Piston
Recommended verification: OEM number, engine model, serial number, old part photos, and dimensions.

Shipping & Returns

Availability: InStock
Shipping: Shipping quotes can be confirmed before payment for heavy or urgent orders.
Returns: Returns are easier when fitment is confirmed before ordering.
B2B support: Bulk, fleet, and repair-shop requests can be handled through the inquiry form.

Frequently Asked Questions

How do I confirm this part fits my machine?

Match the OEM or reference number first, then verify machine model, engine model, serial number, connector layout, mounting points, and old part photos.

Can I order if my part number is not listed?

Yes. Send the old part number, machine plate, and photos through the fitment inquiry form. Support can review possible replacements or alternatives.

Is this an OEM part?

Products are indexed as replacement parts unless explicitly marked otherwise. Always compare reference numbers and confirm fitment before purchase.