400BB Engine

The 440 Pistons sound interesting. I noticed when ordering the Pistons they normally ask for .20, .30, or .60. What do these mean, is this the Diameter of the Piston, or the distance between the Top of the Piston, and the first Ring? Normally do the Cylinders need to be bored for the 440 Pistons, or will they fit as is? Also heard about the Keith Black (KB240) Pistons as another possibility to consider. So I was wondering the same thing, if I need to have the Cylinders bored, or just clean them up.

I'm sorry if this information is already published somewhere on the Forum.

I'm pulling the heads this weekend, and tearing the block down probably next week. I'll post some pics as I get her started.