I have a 2006 silverado with a 5.3 with a few bolt-on's. I have a High output 5.3 sitting in a crate at my house. one of the sleeves in a cylinder was leaking so it was pulled from another 06 model. There was no damage done to the motor, it was found in time. I was woundering if there is any difference in the heads on the HO 5.3 and my 5.3 in my truck, and if there would be a performance gain by swapping the heads? Any advice would be greatly appreciated!

 

HO as in L33 aluminum block? the L33 has 799 heads, are ~64cc where your standard 5.3L LM7 has a 59cc chamber. You gain flow but lose CR unless you mill them a bit.

 

I was told by the tech that pulled the motor it was a "B block". So i dont know if its a L33 or not. Im just now getting into all of this stuff and dont know very much about it. I will try to help as much as possible though. I do know that it is an all aluminum block.

 

the B engine is the L33, yes. It will have 799 heads. Larger combustion chambers and flat top pistons to give it a 9.9:1 CR.

 

Ok! Thank you very much! I appreciate your help!

 

you're welcome