No, Nacho, you still change to KB167 pistons to get the compression up and use .027 head gaskets. The only way to get more CR and use your stock pistons are to deck the block/heads/ and then the intake...way more expensive than just getting the pistons. You can get heads that have the smallest combustion chamber you can find, about 62CC.

True Big Bad Bee, but then you need to ask what transmission is being used. My 318 (original engine) ebody I am building will have close to the "junkyard jewel" setup, but I will be using a strengthened 42RH trans, for the OD gear and the 2.74 first gear. I am planning on a 3.55 rear gear, that will give me the 10:1 spread that is recommended. You take the gear ratio and multiply it by the 1st gear in the trans. You want close to a 10:1.