ROKBLOKZ GMC SIERRA 2500/3500HD STEP-BACK MUD FLAPS
*PLUS, ROKBLOKZ FENDER TRIM CAP KIT!
OEM SPLASH GUARD DELETE KIT INCLUDED: Custom-designed Fender Trim caps included so you can delete the OEM splash guard and keep a streamlined, stylish look - adds a finished look to the fender's edge. $100 value!
WORKS WITH BIGGER TIRES:Main brackets step back so the flap mounts behind the wheel well to allow for the biggest tire you can fit.
EXTREME DURIBILITY: Designed to protect your Sierra HD truck in the harshest environments.
FLEXIBLE (Not Floppy): Bend and flex over any terrain but hold their shape at high speed for unsurpassedprotection against mud, dirt and rocks.
EASY INSTALL: With provided hardware and detailed instructions.
NO DRILLING: Most kits mount using existing OEM mounting locations.
ASSORTED COLORS:Over 10 color options for ultimate personalization.
PROUDLY MADE IN THE USA!
Please factor in 3-5 Business Days for Processing and Assembly.
WHAT'S INCLUDED: Each RokBlokz mud flap set for the 5th generation Sierra 2500/3500 HD comes with 4 Flaps (Front and Rear), ROKBLOKZ Fender Trim cap kit, stainless steel & rust-resistant mounting hardware and instructions to fit factory hole locations. *Does require trimming of the fender to mount bracket and get the most clearance.
WHAT IT FITS: 2020+ 5th Gen GMC Sierra 2500HD / 3500HD
DOESN'T FIT: Not Confirmed for the GMC Sierra 2500 AT4X, AEV Edition GMC Sierra 1500 Any Chevrolet models or previous generations of GMC HD Trucks Any other GMC Model or truck
2 STYLES TO CHOOSE FROM: -RALLYFLAPS were designed for those who like to keep a stock wheel set up but want some paint protection. If your tires rub, you will need our hi clearance step-back kit. -HIGH CLEARANCE STEP-BACK FLAPSmount inside the wheel well and step back past the fenderfor those who run lifts, larger tires and/or higher offset wheels that poke past the fenders and are tight on space inside the wheel well. SEEN ON THE TRUCK IN THE PHOTOS.
Please note that this kit was designed on a stock vehicle. When modifying fenders, wheels or suspension, you may have to modify the flaps to work with those changes. Please email us before ordering if you have any questions.
COLOR OPTIONS: RokBlokz Mud Flaps are available in BLACK, RED, YELLOW, GREY, DEEP BLUE, BRIGHT BLUE, ORANGE, LIME GREEN, OLIVE DRAB, PINK, TAN, and DEEP PURPLE. Colors other than Black are considered Custom as they are made to order.
*NO RETURNS ON COLORED FLAPS Screen resolution, lighting, and surroundings all affect how colors present. If you are questioning how well the color will match, please order a color sample HERE.
Please note that a shopping cart quantity of 1 = a whole kit (4 flaps)
FREE SHIPPINGin thecontiguousU.S. International shipping is available. You can see pricing in the shopping cart. Please note that International Taxes and Duties are the responsibility of the buyer.
CHECK OUT OUR OTHER GMC SIERRA HD ACCESSORIES HERE:
Rokblokz Window Vents are a great accessory for getting airflow to the backseat while keeping bugs and dust out.
We are constantly making small improvements to our products, so yours might be a little different from what you see in photos and videos.
RokBlokz Step-Back Mud Flap Kit for 2020+ GMC Sierra 2500HD & 3500HD: Ultimate Protection and Style
Your 2020+ GMC Sierra 2500HD & 3500HD is built to haul, tow, and tackle tough terrain—but those wide, aggressive tires can throw rocks, mud, and road debris that chip paint and beat up your truck’s body. The Rokblokz Step-Back Mud Flap Kit is designed to stop the mess before it does damage, keeping your Sierra looking sharp while adding rugged functionality.
Built Strong for Real-World Use
Unlike thin rubber or brittle plastic flaps, Rokblokz are CNC laser-cut from our proprietary polymer blend. This material strikes the perfect balance of flexibility and rigidity—tough enough to take hits from rocks without cracking, yet firm enough to hold shape at highway speeds.
They won’t warp in scorching heat, crack in freezing temps, or fall apart under stress. Whether you’re running backcountry trails, towing heavy loads, or just driving daily, these flaps are made to perform in every condition.
And because the flaps are only as strong as what holds them on, our mounting brackets are built to last too. Made from stainless steel and finished with a two-layer powder coat, they’ve got double the protection against corrosion. The stainless underneath prevents rust, while the reinforced powder coat shrugs off chips and wear—so your setup stays solid season after season.
Sleek Fender Trim Cap for a Clean Finish
To tie it all together, the kit includes our Fender Trim Cap—a precision-fit piece designed to replace the bulky OEM splash guard trim. It creates a seamless, finished look while still protecting exposed edges when you pull the liner back for larger tires. No raw cuts or unfinished wheel wells—just a factory-clean appearance that matches your Sierra’s bold styling.
Key Features:
✔ Durable, Flexible Polymer – Resists cracking, warping, and fading ✔ Enhanced Protection – Shields paint, fenders, and undercarriage from rocks, mud, and spray ✔ Fender Trim Cap Included – Replaces OEM trim for a clean, finished edge ✔ Step-Back Design – Provides extra clearance for larger tire setups ✔ Heavy-Duty Mounting Brackets – Stainless steel with a dual-layer powder coat for maximum rust and chip resistance ✔ Easy Install – Uses factory mounting points with included stainless hardware ✔ Made in the USA – Designed, built, and tested for Sierra owners who demand more
Work Hard. Play Hard. Stay Protected.
Whether you’re on the jobsite, off the grid, or out on the highway, the Rokblokz Step-Back Mud Flap Kit with Fender Trim Cap is built to keep your Sierra 2500/3500 HD protected and looking good.
Protect your investment. Upgrade your Sierra with Rokblokz today.
Seeking Local Vehicles for Fitment Testing
At RokBlokz, we’re always looking for vehicles in or near Provo, UT to help us refine and perfect our mud flap designs. If you’re local and want to see if your vehicle qualifies, check out our list of needed models here. Participating owners receive special perks and the chance to be part of our design process!
Fitment
Return Policies
We have a 30-day return policy, which means you have 30 days after receiving your item to request a return.
To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
To start a return, contact us at orders@grocerygetterperformance.com . Once we receive your request, we’ll send a confirmation along with the return address for your order.
If your return is accepted, we’ll send you a return shipping label, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
Damages and issues Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item, so that we can evaluate the issue and make it right.
Exceptions / non-returnable items Certain types of items cannot be returned, like custom products (such as special orders or personalized items). We also do not accept returns for hazardous materials, flammable liquids, or gases. Please get in touch if you have questions or concerns about your specific item.
Unfortunately, we cannot accept returns on sale items or gift cards.
Exchanges The fastest way to ensure you get what you want is to return the item you have, and once the return is accepted, make a separate purchase for the new item.
European Union 14 day cooling off period Notwithstanding the above, if the merchandise is being shipped into the European Union, you have the right to cancel or return your order within 14 days, for any reason and without a justification. As above, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
Refunds We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. If approved, you’ll be automatically refunded on your original payment method within 10 business days. Please remember it can take some time for your bank or credit card company to process and post the refund too. If more than 15 business days have passed since we’ve approved your return, please contact us at orders@grocerygetterperformance.com.
Shipping Policy
Order Processing Time
All orders are processed within 1–3 business days (Monday–Friday, excluding holidays).
Some items may be made-to-order or drop-shipped directly from manufacturers, which may extend processing times. If your order includes a backordered or custom item, we will notify you via email.
Shipping Methods & Carriers
We ship orders using trusted carriers such as UPS, FedEx, and USPS.
Shipping options and rates are calculated at checkout based on your location and selected service.
Estimated Delivery Times (U.S.)
Delivery times vary depending on your location and shipping method:
Standard Shipping: 3–7 business days
Expedited Shipping: 1–3 business days
Please note: these are estimated transit times and do not include processing time.
Large / Freight Shipments
Some items (such as body kits, carbon fiber parts, or oversized components) may require freight shipping.
Freight deliveries may require a scheduled delivery appointment
A signature may be required upon delivery
Customers are responsible for inspecting items upon arrival
Additional shipping charges may apply for residential delivery or limited-access locations.
Shipping Costs
Shipping rates are calculated at checkout based on:
Item size and weight
Shipping destination
Selected shipping speed
Promotional free shipping (if offered) applies only to the continental United States (lower 48 states).
Order Tracking
Once your order ships, you will receive a confirmation email with tracking information so you can monitor your delivery.
Address Accuracy
Please ensure your shipping address is correct at checkout.
We are not responsible for delays or losses caused by incorrect or incomplete addresses
Any carrier fees for address corrections or rerouting may be charged to the customer
Lost, Stolen, or Damaged Packages
If your package arrives damaged, contact us within 24–48 hours with photos of the packaging and product
If your package is lost or delayed, we will assist in filing a claim with the carrier
Once a package is marked as delivered, we are not responsible for theft or loss
International Shipping
At this time, we primarily ship within the United States.
For international orders, please contact us before purchasing to confirm availability and shipping rates.
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If you have any questions about your order, returns, or products, our team is here to help. Contact us directly and we’ll get back to you as soon as possible
Here is a link to a YouTube tutorial on how to delete your full EGR system and install our full EGR Delete. Full EGR Delete Video
How to install the GGP Fuel Pump Plate?
Here is a link to a Instagram tutorial on how to swap your heavy OEM fuel pump plate with your lighter and better-looking fuel pump plate.How To Install GGP Fuel Pump Plate
Here is a user submitted YouTube video on how to install a throttle body spacer on a V6 Camry. How to video on installing a V6 GGP Throttle Body SpacerYou’ll see that you first take off the intake, then unbolt the throttle body from the intake manifold. Once you have the throttle body off you’ll have the option of doing a coolant bypass. If you decide to take the throttle body all the way off you will spill some coolant, but it will not be much. Now, get the GGP Throttle Body Spacer and orient it to where the o-ring is facing the smooth side of the throttle body. Line up the holes and put 2 bolts all the way through. Now with your bolts through, line the spacer and throttle body up against the intake manifold and start to thread your bolts in. Make sure that the o-ring is still properly seated in its groove, then insert the other 2 bolts and tighten all 4 down. Once tight, install your air intake and turn your car on and make sure you didn’t leave any hoses off that might be causing a vacuum leak. If all is good, go for a test drive and feel the lack of throttle lag and your newfound power!
How to install a 4-cylinder GGP Throttle Body Spacer?
Here is a user submitted YouTube video on how to install a throttle body spacer on a 4-cylinder Camry. How to video on installing a 4-cylinder GGP Throttle Body Spacer(2:08 to 5:50 is where the install happens)You’ll see that you first take off the intake, then unbolt the throttle body from the intake manifold. Once you have the throttle body off, you’ll have the option of doing a coolant bypass. If you decide to take the throttle body all the way off you will spill some coolant, but it will not be much. Now, get the GGP Throttle Body Spacer and orient it to where the o-ring is facing the smooth side of the throttle body. Line up the holes and put a bolt all the way through. Now with your bolt through, line the spacer and throttle body up against the intake manifold and start to thread your bolt in. Make sure that the o-ring is still properly seated in its groove, then insert the other 2 bolts and tighten all 3 down. Once tight, install your air intake and turn your car on and make sure you didn’t leave any hoses off that might be causing a vacuum leak. If all is good, go for a test drive and feel the lack of throttle lag and your newfound power!
How to install the GGP Fuel Pump Plate?
Here is a link to a Instagram tutorial on how to swap your heavy OEM fuel pump plate with your lighter and better-looking fuel pump plate.How To Install GGP Fuel Pump Plate
