Got some questions on installing some ls6 heads on my 03 Silverado Z71 5.3. The questions is I know they will fit but I've read some threads that suggest milling down the ls6 heads in order to not lose compression on a 5.3 engine, but exactly how much milling is needed. I am also about to install a VHP "trucker" cam on this truck, will I have any problems with the pistons clearing the heads after the milling?

I would really appreciate any feedback, thanks!