The corsa is a killer bore, for the zuma vertical. Polini's classic 2 ring design, built to last. When you receive this kit, it's clear that your money went into the development department to crank out a quality item. The corsa, is the contessa's bigger, badder brother. Remember that cool kid in high school, that was older than everyone else? The one with the sweet mullet and badass trans am? Well, this is it, if it was a person. If you want the best all around cylinder, with insane reliability, this is it. Here's a youtube video of how a local buddy treats his on a daily. And it won't die..