The aFe Momentum HD Stage-2 intake replaces the factory airbox on the 2011-2016 GM 6.6L Duramax LML with a one-piece sealed housing that has an auxiliary air scoop, a urethane plug to close the scoop, and a roto-molded, dyno-tuned intake tube. The 9 in tall Pro DRY S filter has a 6 in flange, 360 degree radial flow and three layers of oil-free synthetic media for 99.2% cumulative efficiency, wrapped in reinforced metal. It outflows the factory intake by 42% for gains of up to 20 HP and 57 lb-ft. It installs with stainless T-bolt clamps and a silicone coupling at the turbo inlet.
Specifications
| Type | Cold Air Intake System |
| Series | Momentum HD Stage-2 |
| Filter Media | Pro DRY S, three-layer oil-free synthetic, washable and reusable |
| Filter | 9 in tall, 6 in flange, 360 degree radial flow, 99.2% cumulative efficiency |
| Housing | One-piece sealed housing with auxiliary air scoop and urethane plug |
| Intake Tube | Roto-molded, dyno-tuned polyethylene tube |
| Gains | 42% more airflow than the factory intake; up to +20 HP and +57 lb-ft |
| Engine | 6.6L Duramax V8 turbo diesel (LML) |
| What's in the Box |
|
| Fitment Notes | Duramax LML 6.6L engine only |
| Replacement Filter | 21-91059 (Pro DRY S) |
| Emissions | Covered by CARB Executive Order D-550-18 for the 2011-2016 models |
| Quantity | 1 kit |
| Warranty | 2 years on components (original owner) |
| Part Number | 51-74006-1 |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2015-2016 | Chevrolet | Silverado 2500 HD | High Country |
| 2011-2016 | Chevrolet | Silverado 2500 HD | LT |
| 2011-2016 | Chevrolet | Silverado 2500 HD | LTZ |
| 2011-2016 | Chevrolet | Silverado 2500 HD | WT |
| 2015-2016 | Chevrolet | Silverado 3500 HD | High Country |
| 2011-2016 | Chevrolet | Silverado 3500 HD | LT |
| 2011-2016 | Chevrolet | Silverado 3500 HD | LTZ |
| 2011-2016 | Chevrolet | Silverado 3500 HD | WT |
| 2015-2016 | GMC | Sierra 2500 HD | Base |
| 2011-2016 | GMC | Sierra 2500 HD | Denali |
| 2011-2016 | GMC | Sierra 2500 HD | SLE |
| 2011-2016 | GMC | Sierra 2500 HD | SLT |
| 2011-2014 | GMC | Sierra 2500 HD | WT |
| 2015-2016 | GMC | Sierra 3500 HD | Base |
| 2011-2016 | GMC | Sierra 3500 HD | Denali |
| 2011-2016 | GMC | Sierra 3500 HD | SLE |
| 2011-2016 | GMC | Sierra 3500 HD | SLT |
| 2011-2014 | GMC | Sierra 3500 HD | WT |
Documents: Installation Instructions (PDF)
Which engine does it fit?
- The 6.6L Duramax LML in the 2011-2016 Chevrolet Silverado and GMC Sierra 2500 HD / 3500 HD.
Is it emissions legal?
- It is covered by CARB Executive Order D-550-18 for the 2011-2016 models. The EO sticker in the kit goes on or near the intake and is needed for smog inspection.
What is the replacement filter?
- Part number 21-91059, a Pro DRY S filter that can be cleaned and reused.
Is there a Pro 10R version?
- Yes, as part 50-74006-1.
Shipping
- Orders placed before 3 PM EST typically ship the same business day. Larger items ship within 1 to 3 business days.
- Standard, expedited, and overnight options at checkout.
- Oversized items ship by freight and take longer.
- Special order items follow a lead time we confirm with you individually before the order is committed.
- Backordered items ship as soon as stock lands. Lead times are manufacturer estimates and can change. Contact us for current ETAs.
- Need to cancel? Email us right away. Cancellations are not guaranteed once an order is in process. In-stock orders cancel free before they ship; a 6% fee applies only to confirmed backorders and special orders.
- International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.
Returns
- 30 days from delivery to request and ship back a return on new, uninstalled items in original packaging with all hardware.
- Standard returns: 8% restocking fee on the item price before tax and shipping. Shipping is not refunded in either direction. All waived if the item is defective or we made the error.
- Fitment guaranteed: select your vehicle above, or confirm fitment with us in writing before you order. If the part shows as a fit and it is wrong, the return is on us, even after installation. Otherwise, installed or used parts cannot be returned.
- Final sale: special orders, coilovers, electronics, engine internals, turbochargers, superchargers and turbo kits, unless defective or we sent the wrong item.
- Product images may be representative. The SKU and specifications in the listing are what ships.
- Email us for return authorization before shipping anything back.
Full details: Shipping Policy · Returns & Refunds · Warranty






