Are 799 flow numbers the same as the 243?

 

from everything I've heard and can remember.

 

I have a set that I can get my hands on and if its worth it I would swap out my 706 for those

 

you would need to mill them to keep your CR. They have ~64cc combustion chambers but otherwise a good swap.

 

The heads are off a 06 5.3 would I still need to mill them?

 

The heads are of an 06?? Is it a high output 5.3? Cuz 799s came on some Ls6s and 07+ 5.3s.. You would want to mill them about .010 Which is basically just cleaning the surface, And that would net you about 62cc chambers which is close to the 61cc chamber 5.3 heads..

 

Yes. They also came on a limited number of 2005 trucks

The 5.3's with the 799 heads have flat top pistons giving them a CR of 9.9:1

 

as far as i know they are the same... would be a good swap as long as you mill them but i would go 20 thousands or so might as well do it while they are off unless you plan on boosting the engine

 

Ok the 5.3 is out of a 06 envoy it is the all aluminium block I think so is this a high out put? If so I might just get the whole motor

 

The HO is aluminum block in trucks it was a l33 should have flat top pistons too