THE ORIGINAL- LLY INDUCTION OVERHAUL KIT-IOH
The biggest performance flaw with the 04-05 LLY Duramax is the undersized, restricted induction plumbing, specifically the constricted compressor mouthpiece. This applies to all 2500 and 3500HD light duty as well as Kodiak/Topkick medium duty trucks. It indirectly creates an oversupply of discharged compressor heat. Identified in 2007, this flaw is the primary hardware antogonizer of LLY load induced overheating. It is also the flaw responsible for known turbo longevity reduction, and head gasket failure, as described in the following research articles:
THIS AFFORDABLE 6-PIECE INDUCTION OVERHAUL KIT replaces the stock induction tract with a NEW, no-compromise 60% larger, Garrett-approved mouthpiece, machined and adapted for the LLY.
STOCK RESTRICTION (LEFT), NEW DESIGN (RIGHT)
IMPORTANT: ALL parts material rated to 300F. Constructed of high temperature polyurethane and fiber reinforced Zytel Nylon 6,6,: the toughest, most heat resistant known automotive materials. NO RUBBER IS USED! Uses Stainless Steel hardware, temperature rated urethane and nylon.
Factory Warranty Compliant: Retains factory components, the only IOH option GUARANTEED to not void your warranty, these kits have been purchased by GM dealerships for:
- - Immediate performance increase.
- - Reduction of LLY high-load overheating, and increased turbo longevity (lower rpm)
- - 1.5-2.6 mpg towing economy increase (with True CAI)
- - 4-6 psi higher boost number capability,
- - 5-7% average compression efficiency increase,
- - Increased air flow, 10%… decreased spool up time means increased low rpm torque.
- - 150-250 F reduction in peak EGT
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- Installs in 20 minutes with 2 tools, clean factory appearance.
NO MAF re-scaling or tuning, will not interfere with the hood or dip stick location. Includes fully illustrated color install guide, including extra section on benefits and optional tuning suggestions. There is a refundable core charge for the stock parts. The IOH kit is for use with the stock intake or the True Cold Air Intake recommended below. The IOH kit is NOT for use with aftermarket intake tubes. Use the “A-IOH Kit” or “Machined LLY Mouthpiece” below. If you have the stock intake, or the True CAI, the IOH kit is for you. This represents the best flowing system available…anywhere….$325
AFTERMARKET INTAKE IOH: The alternative “A-IOH Kit” is a cheaper option that is compatible with all aftermarket intake tubes. For the best fit, you will be required to cut or modify your own existing intake tube, this kit also deletes the “6.6 turbo-diesel” resonator, with user option to delete PCV. Includes Lifetime Warranty on parts….. $275
Optional High Flow Treatment: By request, specify it separately. For those towing with increased boost, or tuning over 400 HP, using a larger turbo, or to get the best available mpg benefit. Mold tooling leaves areas that can be significantly improved manually. This internal hand machine treatment throughout the entire tract is available for a $75 fee. This custom procedure removes the last possible 15% of restriction in the hard-to-reach places, creates a surface that has less boundary friction………………. $75
HAND MACHINED LLY MOUTHPIECE
Machined MP right
MACHINED MP: A very affordable alternative to the induction overhaul kits above, compatible with all intakes. A hand machined version of the stock mouthpiece that has much better flow characteristics, and steeply reduced flow restriction, similar to the improvements above. There is a $50 core charge, refunded when your existing mouthpiece is sent back…………………………………………………………………………………………..…..……………..$125
IOH PRICING SUMMARY
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IOH.…..…INDUCTION OVERHAUL KIT ($125 core charge not included)—————$325
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A-IOH….IOH KIT FOR AFTERMARKET ($75 core charge not included)—————-$250
- K-IOH…….……………TOPKICK/KODIAK KIT ($75 core charge not included) ———–$225
- HIGH FLOW INTERNAL MACHINING, optional, all kits —————————— add $75
- LLY-MP–HAND MACHINED LLY MOUTHPIECE ($50 core charge not included)– $125
STILL HAVE QUESTIONS? INDUCTION OVERHAUL FAQ’s:
* LIFETIME WARRANTY: All parts guaranteed for life of vehicle, against defect, including heat damage. All IOH kits come with 30 day, no risk, no questions, full refund warranty, excluding shipping.
IOH PRODUCTS CAN BE PURCHASED HERE 
“Michael,
… I’ve put the IOH and the TCAI on the truck. It seems to have dropped the EGT by at least 200 degrees! This is significant for me since I know what overstress can do to equipment. I pay attention to engine parms and will not push the truck above my comfort level (I’ve only let the engine get to 235 before stopping/coasting and letting it cool off)… On the research that you did to discover the cause, very nice and well done! Being an engineer I like to see data that exposes the problem and data that demonstrates the fix. You published enough data that I was convinced that you had discovered the source of this over heat problem, if not the source, at least a major contributitor. The undamped thermal feedback shown appears to indicate classic out of control system – its hard to believe that there were engineers involved in this design. I showed my a neighbor the intake design and sharp unfriendly edge inside the stock LLY intake – he was shocked. He’s an ME that spent several years designing and redesigning components on train engines – including integrating turbo’s on the engines. So anyway, I believe that this will fix the cause, not the effect (such as the V2 mod I’ve read so much about). I plan on towing this month (27ft toyhauler) and will get some read on the temp improvement.” Cory Reche
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“Hello as I said to you be4 I would let you know after pulling my trailer with the new turbo mouth piece that i had installed on my LLY engine I didn’t have a exhaust temp guage so I don’t know about temp being lower at this point but the engine does puller stronger, its does not shift as much either and when it does down shift to 4th it pulls stronger the MPH do not drop as much either pulling the hill, the engine always did pull well but does it under cooler conditions I have a under bumper cold air scoop & I sealed off any hot air from under the hood. I am thinking if I keep the truck I will have loovers cut into top of hood for futher heat reduction. Thankyou again for your good reply & speeding service.” Michael Marcocchio