Picture 1 of 5

Stock photo

Spark Plug Motorcraft SP-421 fits 2006 Ford F-550 Super Duty 6.8L-V10 - Picture 1 of 5

Spark Plug Motorcraft SP-421 fits 2006 Ford F-550 Super Duty 6.8L-V10 - Picture 2 of 5

Spark Plug Motorcraft SP-421 fits 2006 Ford F-550 Super Duty 6.8L-V10 - Picture 3 of 5

Spark Plug Motorcraft SP-421 fits 2006 Ford F-550 Super Duty 6.8L-V10

4.2921 product ratings

ChasinParts (22865)

97.9% positive feedback

Price:

$15.23

Free shipping

Estimated delivery Tue, Apr 15 - Sat, Apr 19

Returns:

30 days returns. Buyer pays for return shipping. If you use an eBay shipping label, it will be deducted from your refund amount.

Condition:

New

Portions of the part information on this page have been provided by WHI Solutions, Inc. Manufacturer Warranty. Warranty Type. Warranty Duration. ChasinParts has both the product selection and quality range to fit diversified needs.

Ratings and Reviews

Learn more

4.3

21 product ratings

17 users rated this 5 out of 5 stars
0 users rated this 4 out of 5 stars
0 users rated this 3 out of 5 stars
1 users rated this 2 out of 5 stars
3 users rated this 1 out of 5 stars

Most relevant reviews

See all 20 reviews

by tmo_us_dhzov3tu
Feb 19, 2024
Stay away from seller!!!!!
I originally gave this product 5 stars but I need to change it after only 3 days my truck is destroyed! The spark plugs are failing when I drive up the hill to get to my home, I’ve already replaced 4 and 2 more just failed. The worst part is the ceramics on the diode broke off into my cylinder head and is destroying my engine!!! Stay away from this seller I reported them to the FOMOCO AND BBB, they are selling fake knock-off spark plugs/damaged items
Verified purchase: YesCondition: New
by roberbowle_3
Jan 19, 2024
Fakes
Very, very, very good replicas of genuine ford plugs. Actually only one sign of fakes but perhaps the most important as it in the integrity of the plug itself. Can't be to mad about the price. Bassicaly just bought cheap plugs with the potential illusion of true genuine plugs.
Verified purchase: YesCondition: New
by jort3205
Feb 15, 2024
Great products
Price main reason for purchasing. Direct fit noticed difference once installed.
Verified purchase: YesCondition: New
by jejoh389547
Mar 22, 2025
Unbelievable price
Got great price for quality parts
Verified purchase: YesCondition: New
by 451149
Jul 20, 2023
I enjoy good product
great fit
Verified purchase: YesCondition: New
by sandranay2
Oct 04, 2023
Good quality
Loved the price for good quality and early shipment.
Verified purchase: YesCondition: New
by richard.alan
Jun 30, 2023
working as they should
product was as described and working well.
Verified purchase: YesCondition: New
by trco-2560
Mar 06, 2024
Wont order again
it took to long to get haven’t had time to put them in if i got them two weeks ago would have them in by now
Verified purchase: YesCondition: New
by reingre
Jul 31, 2024
Great price
Good stuff
Verified purchase: YesCondition: New
by schol_jos
Aug 31, 2021
Farm truck
Help greatly thank you
Verified purchase: YesCondition: New