This thread is purely informational, as I don't plan on getting any of these in the near future. I was just curious what the differences in these products are, and what benefits/problems each might have.

I know what engine sleves are, and how they work... couldn't find a good pic tho.

here's a block girdle:


I have no idea how this works, and couldn't really tell how its installed by the pictures.

here's the block guard:


This just goes around the top of the cylinders, but leaves the stock cylinder walls in place, unlike the sleve which lines the whole combustion chamber with iron. Is this any good? Is just reinforcing the top enough to keep the block from cracking?

I'm assuming the sleeves are probably the most effective option, have no clue about block guard or girdles tho.

ideas/input