The intake & exhaust manifold must be removed. Then the head must must be removed. A very difficult repair and not a repair a novice should attempt.
The Duramax is a General Motors diesel v8 engine. There are five types of Duramax engines: LB7, LLY, 2006 LLY, LBZ, and LMM. The 8th number on the VIN number will identify the engine type.
(Lb7) 300 (LLY) 310... 320 on LLY's put in trucks in 2006-2007 (LBZ) 360 (LMM) 365
(Lb7)300hp (LLY)310hp and 320 hp on LLY models put in 2006-2007 trucks (LBZ)360hp (LMM)365hp
If the 8th digit in the vin number is a 2 then it is an LLY, if the 8th digit is a D then you have an LBZ
If the truck is earlier than 2006, than 310hp. If it is 2006-2007, than 320hp.
If it was an earlier 2004 truck with the Lb7 duramax (8th digit of VIN would be 1) then it has 300hp. If it was a later 2004 truck with the LLY duramax (8th digit of VIN would be 2) then it has 310hp.
LB7=520 LLY=605 LBZ=650 LMM=660 all are in lb-ft
depends on which engine you have. 2004 was the transition year. look at the eighth digit in your vin # if its a "1" you have a LB7, if its a "2" you have a LLY. LB7 300hp 520ft tq LLY 310hp 605ft tq
Lb7=01-04.5 lly=04.5-05 lbz=06-07 lmm=08-10 lml=11-??
The stock boost pressure for a 2005 Chevrolet Duramax 2500HD with the LLY engine typically ranges from 15 to 22 psi under full load conditions. This turbocharged 6.6-liter V8 diesel engine is designed to deliver optimal performance while maintaining efficiency. Variations in boost levels can occur based on factors such as altitude, load, and engine condition.
It's doable... not sure how feasible it would be. You'll need the complete ECM and EGR from the 06 engine.... the 2002 would have the pre-ACERT LB7 engine, whereas the 2006 would be either the 6.6 LLY or 6.6 LBZ (depending on when in 2006).
Pros: Healthier engine, cleaner intake, increased performance, increased mileage. Cons: It's illegal. and may void any warranties