They give like no credit to the stock girdle that's in all B18C blocks. Sure, the Z10 one is nicer but I've never heard of the stock one failing or causing any problems. The only application where I'd say to go out and buy one of these is if you're using a longer stroke than a B18C (i.e. LS/CRV crank & rods). Even then, if you shell out for some forged rods--which generally come with ARP bolts--the girdle is kind of unnecessary. Eagle rods are like $365 and Crower "econo-billet" rods are about $400, so I'd be more inclined to just beef up the rods and call it a day.