I have a 2001 silverado with the 5.3 its tuned has a cai and exhaust. But here lately I have been wanting to do a little more I found a medium size garret turbo i am buying (family deal) and before I do that I am wanting to change the cam what lift duration can I use on stock valve springs? i dont want anything radical just a little bit more than stock. also do i HAVE to remove the heads to change the cam? thanks

 

No need to remove the heads. Also I would atleast do ls6 springs and hardened pushrods no matter the cam size.

 

Unless the cam has over .550 or .570 lift... depending on which LS6 springs you pick up, I don't think that the argument has ever been settled on what their max lift actually is.

 

There's an easy way to settle it then. .550 is the max lift that is not questionable.
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will the lifters fall? i thought they would fall in once i removed the old cam? and the only way to get to them in an ls is to remove heads right?

 

They might. Some people use dow rods to hold them in place. And yes you have to pull the heads to get to the lifters.

 

They are in cups, once you pull the rockers and pushrods out, all you have to do is spin the engine over a couple of times and the lifters should stay held up by the cups. They make a tool that fits in two holes in the front of block to make sure they don't fall, but you can just use good sized dowel rods.

 

Should, but don't always. I've heard of guys using the dowel rods, I've also heard of people using pen magnets to hold them up.

 

z06 cam with ls6 springs. crane also has a boost cam with 551 lift that would work well.