I am starting an LS6 build and will probably be running forced induction at some point. Was wondering what would be the best way to get a lower compression since the ls6 has a higher compression ratio of 10.5:1. Some other website said to start with the 6.0L truck heads, but after that there is no information about it.

 

Air Assault!

LQ4 heads have bigger chambers and will drop the compression ratio, but I'm not sure about compatibility with the LS6's smaller bore diameter. Dished pistons and 241 heads are a sure thing, but check in the Forced Induction forum here for more info.

 

The #317 cast heads are 72cc compared to the #243 64cc head ran on the LS6. That would be the easy way to lower your compression.

 

the truck 317 heads bolt up and will lower the scr. but must use a 4.00 bore gasket. go with ls9 gaskets if plan on future forced induction

 

Just like 243s fit (and come from the factory) on the LS1/LS6 bore, then LQ4 heads will also fit as they are basically the same head except with a bigger chamber.

Get some LQ4 heads, have some bowl work on them done to increase the volume, and get a thicker headgasket. That should work pretty well and you don't want to lower the compression too much unless you're running lots of psi. And if you're running lots of psi then you won't be doing that on the stock rotating assembly anyway.