I have a complete lly from an 04.5, I was wondering what parts are interchangable with the lbz. I realize all the electronics are different, what about the top end and bottom end???

I had heard that the head design is a tad bit different along with the LBZ internals are supposed to be a bit stronger to handle the extra power but all in all they are practically the same engine...prolly more electronics emissions on the LBZ but don't take my word for it.

So the bottom end would interchange, what about the heads????

here is a few things on what GM says they have done to improve the LBZ:
LBZ Improvements
To reliably achieve an increase in 50 horsepower with 45 ft/lb torque, the Duramax ™ diesel had to be revised in many areas. A few of the revisions on the 2006 LBZ were:

• New pistons with a revised compression ratio.

• Wrist pins that are larger in diameter.

• Connecting rods with added material to increase the I section strength.

• Engine block and machining changes

• Cylinder heads

The heads will retrofit backwards, but not forwards. LBZ injectors wont fit in LLY heads without modification.

LBZ reluctor wheel is NOT the same, must be switched.

LBZ front cover/water pump NOT the same, can be used, but since its apart to swap reluctor, switch it.

Can I put LBZ turbo on LLY without any mod?

Can I put LBZ turbo on LLY without any mod?

i believe you can. i dont think GM has changed any of the VVT chargers.