Originally Posted by regular guy
You just need to make sure the CP pistons are compatible with the Alusil block. It's very likely CP has some compatible pistons because they've been serving the Porsche guys with similar blocks for a while. But you definitely want to check before buying. Mahle pistons (factory) are also very high quality, some say they are as good as they get. But they are much more expensive as well.
I meant if you sleeve it you could use those other pistons, you Can Not use them the a stock block.